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I want to become a white whistle soon so I can catch up to my mother...and explore the places she went.


Riko is a 12-year-old[1] orphan from the town at the edge of the Abyss, Orth. She's the only child of the White Whistle Lyza, the Annihilator. When she was two, her mother went missing during an expedition to the bottom of the Abyss, and since her father, Torka, had died before she was even born, she was left under the care of the Belchero Orphanage.

Her dream is to become a White Whistle, a legendary type of Delver, and explore the depths of the Abyss in order to learn its many secrets and to find her mother.


Riko is a short girl with a plain face, green eyes, and long blonde hair styled in two ponytails. She gained a prominent scar on her left arm after Reg tried to amputate her arm in order to save her from the effects of Orb Piercer poison in the 4th layer.[2] While delving in the Abyss, she wears a delver jacket and hat over a leotard. In Orth, she would wear a white blouse. Riko always wears glasses.

In Ilblu, she cuts her hair short.[3]


Riko is a good-natured, joyful, and energetic child. She has a quick and inquisitive mind, gathering and properly organizing all the information available on subjects that interest her. For the team, she is the unbreakable force of enthusiasm in the midst of their constant hardships.

The Abyss excites her to no end. Growing up, she diligently studied to become a Delver like her mother was, enchanted by its mysteries and secrets. By the age of twelve, she had become an Apprentice Delver with the right to explore the shallowest level of the Abyss on her own.

Compared to Reg, she is fragile and not much of a brawler, but her ability to keep a cool head under pressure to make rational decisions allows her to tackle the Abyss, even without assistance from the team.

Her priorities are her own wants, so she has made and suffered from rash actions. She can also make a delicious meal out of anything, is willing to eat disgusting food, and has no sense of personal space.


Spoiler warning: The following section contains spoilers. Read with caution.

Unheard Bell Flashback Arc Edit

When her mother had just become pregnant with her, she was ordered to lead an expedition squad to retrieve a Greater Relic from the 4th layer, the Unheard Bell. The expedition was long and bloody, with many confrontations with delvers from other nations which resulted in the deaths of many members of the platoon, including Lyza's husband, Torka.

Eventually, Riko was born in the depths of the Abyss near the end of the mission after the decimated group had obtained the Relic. It all took a turn for the worst when Riko was stillborn, throwing Lyza into a severe depression. Lyza's mentor Ozen was so annoyed at the dead child for having sent Lyza into such a state and delaying their mission to retrieve the Unheard Bell that she shoved Riko's corpse into the Curse-Warding Box so that she wouldn't have to deal with it. However, much to everybody's surprise, sounds started coming from within the box, and when it was opened, Riko was revealed to be alive.

Having confirmed her newborn's resurrection, Lyza helped Ozen carry the extremely heavy Curse-Warding Box from the 4th layer up to the Seeker Camp. Riko was brought to the surface, where she lived a healthy childhood in Lyza's care and in the care of Jiruo when Lyza was not around.[4][5][6]

Riko's identity as the daughter of Lyza the Annihilator was kept secret due to her mother having many potential enemies that could threaten her. When she was 2 years old, her mother descended on her "Last Dive" towards the 6th layer, and Riko was taken by the Belchero Orphanage under the care of Lyza's apprentice, Jiruo.[7]

Orth ArcEdit

While exploring and delving at the 1st layer, Riko is being chased by a Crimson Splitjaw, when a beam of energy hits it and chases it away. Wondering who saved her, Riko follows the wreckage from the beam to its source, where she finds an unconscious Reg. Upon further inspection, Riko realizes he is not human, and with the help of Nat, she brings Reg back to Belchero Orphanage. There she studies and takes notes on Reg's body and is able to wake him up using a jolt of electricity. She gives Reg a name, helps him settle in at the orphanage, and tells him about Orth and the Abyss.[8]

During the Resurrection Festival, a celebration of returning delvers[debatable], Hablog returns from the Abyss with the white whistle that belonged to Riko's mother, Lyza, along with some of Lyza's notes from her delving experiences. While Riko and Reg look through them, they notice one of them contains a sketch of a figure that looks like a silhouette similar to Reg, along with a note reading "I'll be waiting at the bottom of the Abyss."[9] After discussing it with Nat and Shiggy, Riko and Reg decide to leave Orth and go to the bottom of the Abyss on their own. The two take a few days to prepare and then leave the orphanage in the middle of the night. When they reach the Wharf district, a part of Orth that dips into the Abyss, Riko and Reg say their final goodbyes to Nat and Shiggy, and begin their descent towards the bottom.[10]

Descent to the Abyss ArcEdit

After the sad goodbyes from Riko and Reg to Nat and Shiggy, they finally descend and land somewhere in the 1st layer of the Abyss, with a depth of 820 meters.[11] While they are eating their breakfast, Riko notices Jiruo stuck a red slip with the contents of Lyza's sealed letter and the message, "I'll depart at dawn to capture you", into their belongings: Riko rushes and packs their things with Reg's help, and they leave the premises post-haste.[12] Immediately afterwards, they land in a Silkfang's territory and are ambushed by it; however, they escape while defending themselves.[13] They witness the 2nd layer for the first time. Reg suddenly hears his own voice—something about his past–and later, he accompanies Riko for a short break. While they are having a conversation, Reg sees a delver above some boulders who chases them while they rush to escape and hide—Reg defends Riko. Not very much later, the delver catches up—and is revealed to be the Black Whistle Delver Hablog, who was impressed by the group's fast pace. Hablog's main objective was to meet and inspect Reg because Nat and Shiggy told him about Reg's true nature. Instead of taking them back to Orth, he offers to escort them to the Seeker Camp, which Riko declines. He then gives Riko a warning about Ozen, some medicine, and other supplies and lets them go.[14]

Shortly after they arrive on the 2nd layer, Riko and Reg hear a cry for help, but it's one of a Corpse-Weeper, which mimics it's victims cries of pain and fear: they follow it. While observing the Corpse-Weeper, they are ambushed by a colony of them, and one of them snatches Riko. She struggles initially, but she loses consciousness due to the strain of ascension. Reg, unsure of what to do, recalls his memory of using the Incinerator to save Riko from the Crimson Splitjaw in the 1st layer. Instinctively, he raises his arm and fires his Incinerator, obliterating the colony of Corpse-Weepers and saving Riko from being fed to the Corpse-Weeper's young.[15]

Seeker Camp Arc Edit

After a short climb down the top of the 2nd layer, Reg and Riko find themselves in the company of the Immovable Lord, Ozen, at the Seeker Camp; the job she has taken on is to supervise descent past the 2nd layer. While in the presence of Ozen; Riko and Reg make friends with Marulk, Ozen's pupil and servant. During their stay, Ozen lends them blue whistles in return for Lyza's white whistle. Later on, Riko learns from Ozen about her birth in the Abyss and that she was a stillborn that only survived due to the Curse-Warding Box.[16]

Ozen says that beings put into the Curse-Warding Box aren't protected against death, that they indeed die but are resurrected, now longing to venture into the Abyss. She confirmed this by putting a piece of meat they had for dinner into it, which began moving and then, after a while, stopped. Ozen continues to agonize Riko by assuming she probably also will stop moving at some point. Hearing that, Reg steps in and tells Ozen that she has gone too far, and a fight erupts between them, one-sidedly in Ozen's favor. Riko tries to deescalate the fight but is promptly knocked out with a flick of Ozen's hand. Reg arrives at the conclusion that only a shot from his Incinerator will be able to beat Ozen. Then he tries to use it; however, as Reg is charging it, Ozen nonchalantly grabs his hand and points it at Riko. Reg immediately wrestles his hand free, and Incinerator is discharged, blowing a hole in the wall. Ozen then stomps him until he fells unconscious as Riko can do nothing but helplessly watch.[17]

At some point in the fight, Marulk panics and goes to get the other Subterranean Bandits. Afterward, it's revealed that Ozen was trying to provoke Reg and Riko into a fight in order to test if they are ready to make their way further down the Abyss. She tells them that in their current state, sooner or later they'll die. As such, she instructs both of them to stay three weeks in the forest behind the Seeker Camp as survival training.[18]

During their survival training, Riko and Reg learn to be more adept and aware of their strengths and weaknesses. Reg and Riko return to the Seeker Camp after ten days, and Marulk congratulates them on passing, as he cried on his first day of training. Ozen also tells them about Abyssal time dilation, implying that because time moves more slowly the lower one is, Lyza might be alive. Afterward, Riko and Reg leave the Seeker Camp to advance down to the 3rd layer.[18]

The Great Fault Arc Edit

Riko and Reg descend the 3rd layer, the Great Fault, which features a long, vertical shaft. The trip is made more dangerous by Madokajacks constantly seeking prey. Fortunately, there are plenty of Neritantan who make nests in the holes along the shaft. Riko uses them as a distraction to draw the predators away. Riko and Reg run into the very same Crimson Splitjaw that Reg saved Riko from previously. Reg recalls Ozen's warning: using the Incinerator causes Reg to fall asleep within ten minutes, and for two hours afterward, it is impossible to wake him up. This would leave Riko completely unprotected, so if Reg uses the Incinerator, he must make absolutely sure that he defeats the threat before him. Riko recalls that the Crimson Splitjaw eats Relics, so she throws one to distract it, allowing Reg to attack from below. He knocks the Crimson Splitjaw into the shaft, where it is attacked by several Madokajacks.[19]

Poison and Soul Liberation Arc Edit

During Riko's and Reg's descent to the 4th layer, they are attacked by an Orb Piercer. In the battle, Riko's hand gets stabbed by one of the Orb Piercer's venomous needles. Reg prepares a makeshift tourniquet out of some rope to restrict the poison spreading to other parts of her body. Having no way to retaliate, they decide to flee by ascending with Reg's arms. The thus-incurred strains of ascending of the 5th layer and, because of the proximity to it, 4th layer causes Riko to bleed out of every orifice in her body and hallucinate. Riko instructs Reg to cut off her arm to stop the venom from spreading, but because of Reg's hesitation, he makes a crude cut, causing more harm than good. Shortly afterward, Riko loses consciousness, leaving Reg in despair. [20]

Nanachi reveals themself to Reg, due to seeing him crying over Riko's body. Because the two's relationship reminds Nanachi of their relationship with Mitty, Nanachi decides to aid them, gives Reg instructions to resuscitate Riko, and takes them to Nanachi's hideout. During their stay, Riko is in an unconscious state and only recovers after she receives the medicine Nanachi made for her.[21]

As part of convalescing, Nanachi brings the duo to a hot spring with healing properties, where Riko and, due to Nanachi's insistence, Reg take a bath. Riko requests Reg's help with undressing because she can't do it herself with only one working arm—Reg's quite embarrassed about the idea. They enter the spring, and after a while, Riko asks Reg, "What's up with your penis?" Nanachi points why should Reg be so fickle about this when he had already kissed Riko, referencing the mouth-to-mouth resuscitation, and after that, finally leaves them alone.[22]

In the recovery process, Nanachi has to fix Riko's arm injury caused by Reg's unseemly cut. This process is painful and leaves Riko's arm debilitated and with a scar. Reg's ashamed and very sorry for it, but Riko replies that the scar is a testament to Reg's devotion to her, that even though Reg cried and agonized about what to do, he protected her.[23]

Ido Front Arc Edit

After preparations, the group embarks from Nanachi's hideout, reaching the field of Eternal Fortunes. There they encounter one of Bondrewd's Umbra Hands.[24] A brief exchange follows, in which the Umbra Hand tells them that the field is to be burned down due to an Amaranthine-Deceptor infestation and that Bondrewd is expecting them. As the burning commences, the Deceptors swarm and attack the group; however, Riko is unscathed.[25] Then the three of them reach Bondrewd's base, Ido Front. A girl, Prushka, approaches them and asks if they are her father's guests.[26]

A few moments later, Bondrewd arrives, greets the trio, and informs them that entrance into the 6th layer is only possible with a personalized white whistle. He invites them to stay a night and Prushka gives them a tour of the base.[27] During the night, Riko searches for a bathroom and almost is inflicted with the curse due to trying to go up a staircase but is saved by Prushka. The two of them spend time afterwards, become friends, and Prushka introduces Riko to her pet: Meinya.[28]

Later on, both of them find the room Reg is in. Nanachi has already arrived before them, and they are shocked as the Umbra Hands experiment on Reg, having already cut off his arm. Prushka orders the Umbra Hands to stop treating her father's guests that way, only to be informed by them that this area is off limits for her.[29]

The trio, together with Prushka, flees outside Ido Front and escapes on a boat. Only Prushka stays back, because she wants to convince Bondrewd to return Reg's arm.[30]

Riko is visibly distraught and cries about the suffering put upon Reg by the Umbra Hands. Reg, lying injured, mentions he can smell the burnt parts of Netherworld Stew. Riko extrapolates from this and other signs (including her mother's notes) that they are located near a Stingerhead nest; the trio uses this to create a trap for Bondrewd.[31]

Reg, Nanachi, and Riko are confronted by Bondrewd and his Umbra Hands again; however, they have been let into the trap by the trio and thus are attacked by a colony of Stingerheads.[32]

Only Bondrewd survives the attack with his Sparagmos, but is taken care off by a clever strategy of Nanachi and Reg resulting in him being exposed to the curse as well as being crushed by Reg with a boulder. Moments later Prushka and an Umbra Hand arrive. Prushka bursts out in tears over the state Bondrewd is in. The Umbra Hand quickly removes Bondrewd's mask and replaces it with his own, leading him to turn into Bondrewd in the process.

Bondrewd makes the relieved Prushka pass out and reveals to the trio that all Umbra Hands are copies of him he can transfer his consciousness into. After a quick beatdown, he leaves them and invites them back to the Ido Front whenever they are ready.

Riko notes that Bondrewd maybe uses the artifact, Zoaholic,to transfer parts of his consciousness. Together with Reg the both make a strategy in order to destroy it. As they sneak back into Idofront Nanachi and Riko make their way into what Nanachi calls the processing room. They explain to Riko that Bondrewd's cartridges are made from living humans removing anything but the organs needed to sustain life. Moments later Bondrewd shows up and invites Nanachi again to join him, due to being interested in her "blessing".

He is quickly interrupted by Reg, who has absorbed the power plant's reserves and thus went out of control. A fight between Reg and Bondrewd breaks out. Only due to Nanachi's interruption, due to not wanting to see Reg in such a state and begging him to stop with a hug, the fight comes to a momentarily halt; with Reg turning back to his usual self.

During the second stage of the fight, Bondrewd reveals that he turned Prushka into a cartridge. This revelation causes Riko to be shaken up to tears because Prushka was a good friend to her. After Bondrewd's defeat, resulting him to be cut in half, Riko holds Prushka's cartridge close to her and cries. At that moment, a stone, like one needed to craft a personal White Whistle, comes out of the cartridge. Nanachi tells Riko that Prushka most likely assumed the form of the stone to be able to travel along with Riko, which relieves Riko a bit. Nanachi makes a harness so Riko can wear Prushka's stone around her neck.

As the group gets ready to traverse into the 6th layer, it is shown that Bondrewd's consciousness still lives on within his Umbra Hands as they come to see Riko's group off.

Ilblu Arc Edit

Riko's group uses the altar connecting the 5th to the 6th layer. On their way down, they see various creatures and later, after leaving the elevator, decide to make camp for the night. Nanachi awakens and notices something invaded the camp after they had fallen asleep and stole Prushka's stone.

With the help of Meinya, they track it down to a village. The being that took the stone introduces itself as Majikaja and tells them that it only took Prushka's stone to get it worked on by a jeweller in order to make it into it's finalized form. While they are waiting, Majikaja explains a few things about the village, Ilblu, and brings them to a market.

Due to an accident, Meinya is injured by a very curious Narehate and the group witnesses the village's ritual to balance value. In the ritual, the Narehate at fault for Meinya being hurt gets stripped off it's belongings and even parts of it's skin. Afterward, they manage to stay at a hotel but split up after hearing a loud sound that Reg wants to investigate, while Nanachi and Riko stay behind. Later on, Nanachi decides to go and try to buy water and some fruit. Riko stays back alone at the inn, but after a while decides to go search for Nanachi and Reg.

While doing so she slowly draws attention to her from the villagers until they start to swarm her out of curiosity. Just before Riko is overwhelmed, by the sheer amount of villagers; the Narehate from the value ritual, Maaa, pulls her to safety. A brief exchange follows that clears up Maaa is kind, can only communicate with gestures, and feels very bad about hurting Meinya. Maaa tags along with Riko and shows her to a restaurant. Riko tries the restaurant's food and is very pleased with the taste. As she wonders about the dish she just had, the chef of the restaurant, Moogie, informs her about it. Riko is very surprised that Moogie speaks the human language because the Narehate of the village have their own and the only other villager capable of it, so far, was Majikaja. Moogie informs her that some individuals in the village are still able to speak the human tongue; like The Three Sages, the founders of the village. She also informs her that one, Wazukyan, is sitting right next to Riko.

Riko hastily introduces herself to him, with a big bow, thinking she had been very rude due to not knowing that he was someone so important. Wazukyan responses very laid back and even gives Riko a high five before leaving. Afterward Moogie teaches Riko some basics of the Narehate language. During that Riko asks her if she had an idea where her friends could have wandered off to. Moogie tells her that they could have gone to the edge of a village since there is a deep cave to explore. Riko makes her way to the cave and descents into it. She finds a bound person there. Riko asks her who she is and why she is imprisoned in this cave. The person introduces herself, timidly, as Vueko and she was imprisoned by the sages for being against the founding of the village.

After a short chat, in which Vueko reveals that she supposes it isn't so bad a place now, Riko releases her since she doesn't seem to be a bad person. Afterward Vueko, in disguise, travels back to the village with Riko. Vueko is also able to figure out where Nanachi might be and sends Riko to the house of Belaf, another sage. Riko visits the sage and finds Nanachi and Mitty with him. Belaf tells her that the Mitty he has is a clone created from the original brought by Bondrewd to the village whom he wanted to use as a nutrition source—because he couldn't afford to buy Mitty directly from him, he sacrificed half of his body to have the village replicate her.

In a short flashback, it's shown how Nanachi is moved to tears out of happiness to be reunited with Mitty, and how they are shocked moments later as they watch how Belaf extends his feelers to drink from Mitty. Belaf tells Riko that Nanachi offered themself up to him in exchange for ownership of Mitty so that Belaf couldn't drink from her anymore, and that he is willing to sell Nanachi back to Riko if she can give him something of similar value. He suggests to Riko to trade both her eyes, both her legs or her complete digestive system to him. Before Riko can answer him Majikaja closes up her mouth and tells her not to be hasty. Riko gives, dejected, up for the moment and returns to Vueko.

Before she can think about what to do any further the village is suddenly attacked by a Fuzosheppu. A short fight between Juroimoh of the sages and the creature occurs, which Juroimoh loses due to misjudging his surroundings. As Riko watches other villagers try to stop the Fuzosheppu she makes up her mind to stop the creature and comes up with a strategy. She lures the creature into the middle of the village, surprises it with a mirror image of itself, has the villagers capture it with a net and attack it from all sides. The Fuzosheppu, however, manages to burst out of the net and Riko is saved again by Maaa, who pushes her to the side and is grabbed by the creature instead of her. As Riko desperately thinks of a way to save everyone she sees an image of Prushka telling her to blow her whistle.

Shortly after she does Reg arrives at the scene ready to fight the Fuzosheppu. As he lunges at the creature, it collapses and Wazukyan shows up telling Riko and Reg that the Fuzosheppu is already dead and explains the nature of it. Riko asks him if he knew of a way to get enough value to buy back Nanachi from Belaf. Wazukayn tells them that if they had a body part of Faputa, it might be possible, and Reg decides to go ask her because he met her before when he was investigating the lound sound. Meanwhile Vueko tells Riko and a few villagers about her backstory.

After Vueko has finished telling her story all of the listeners look truely surprised. Vueko tells them Faputa has inherited the three Cradles from Irumyuui and thus Irumyuui lost the power to maintain the village, but is kept alive by the new value brought in by visitors of the village. Faputa is trying to free her mother, Irumyuui, which would mean the destruction of the village. She also tells them it is not easy to leave the village after having entered it once. Riko asks her if it’s possible to convince Faputa from abandoning her wish to destroy the village, but Vueko tells her she most likely wouldn’t listen. Riko also asks what Vueko is going to do now and Vueko responds that all she wants to do for now is not forget Irumyuui.


General Knowledge Edit

Riko's obsession with the Abyss lead her to read about it extensively. She has a lot of general knowledge about each layer and its creatures and plants. She has memorized almost all known Artifacts and their functions. She is a quick learner and experienced Delver who knows many survival tips.

Cooking Edit

She can cook food with a great taste, even with unfamiliar ingredients found deep within the Abyss.

Approachability Edit

Riko's joyful attitude and curiosity make it easy for her to quickly make new connections with people, as seen with Moogie, but can also be considered naive.

Trivia Edit

  • Riko is the only known person to be in possession of two White Whistles (Prushka and Lyza’s).
  • She is the only known White Whistle who is not officially recognized by Orth or the Delvers' Guild, due to the fact that she was only a Red Whistle when she started her journey. As she can never return to Orth, her White Whistle will never be officially catalogued, unless a witness travels up to Orth and reports it.[Speculation]
  • She is the only known White Whistle to skip every other stage of progression in Whistle advancement and is likely the only delver to ever receive this rank while still a child, outstripping Lyza who received it while being a young adult.
  • She is the only known living being who was resurrected by the Curse-Warding Box and hasn't died shortly thereafter; however, her lifespan may be limited.
  • Her desire to explore the Abyss may be partially from the Curse-Warding Box, as all life resurrected by it instinctively seek the centre of the Abyss.
  • She has experienced every curse up to fifth layer's.
  • Riko is a name of Japanese origin, it means "child of white jasmine".[33] Curiously, the Resilience Flower has many similarities to the jasmine flower.

References Edit

  1. chapter 6, page 7
  2. chapter 26, pages 2–4
  3. chapter 46, page 32
  4. chapter 5, pages 12–14
  5. chatper 14, pages 12–17
  6. chapter 16, page 12–13
  7. chapter 16, pages 13–16
  8. chapters 2–4
  9. chapter 5, page 21
  10. chapters 5–8
  11. chapter 9, page 3
  12. chapter 9, pages 9–12
  13. chapter 9, pages 12–14
  14. chapter 9, page 17–chapter 10, page 10
  15. chapters 10, 11
  16. chapters 12–17
  17. chapters 14–15
  18. 18.0 18.1 chapters 16–17
  19. chapter 18
  20. chapter 18–19
  21. chapter 21
  22. chapter 25
  23. chapter 26
  24. chapter 26
  25. chapter 27
  26. chapter 28
  27. chapter 29
  28. chapter 30
  29. chapter 31, pages 1–6
  30. chapter 31, pages 6–11
  31. chapter 31, pages 12, 13, 17
  32. chapter 31, pages 14–19
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