Nanachi (ナナチ, Nanachi) is a Narehate; a person who survived the 6th layer's curse of the Abyss, and was left deformed as a result, but, unlike most other narehate, still retained a sound mind. Possessing vast knowledge of the Abyss - its ecosystem, vegetation and even the use of the medicines, Nanachi is currently a part of Riko's party, assisting her in reaching the bottom of the Abyss.
Nanachi's appearance is very rabbit-like, save for a long sturdy tail and human-like hair; which is straight and white or cream in a short bobbed style, the sides of the bangs going down to the shoulders. In contrast, medium tan fur covers the rest of Nanachi, with light tan covering the insides of their ears and belly. They have a blush-like spot on each cheek; which has two thick whiskers protruding sideways. Other animal traits include a cat-like mouth with little fangs, yellow eyes with horizontal oval shaped pupils (similar to a goat's) and erect bunny ears. Their fingers are rather stubby.
Nanachi's attire consists solely of gray-green, baggy, drop-crotch harem pants, with dark-pink hip-bags on both sides, red pant legs, and a pink flap that is supposed to cover their usually naked torso.
Nanachi also wears a large, oddly-shaped headpiece the same colors as their pants. Attached to the sides of it are two curved horns that stick out horizontally. Hanging from the back there is a large layer of what appears to be shingles, covered by a layer of cream-colored animal pelts, and then another smaller layer of shingles. Strangely, Nanachi's side bangs seem to be much longer when the helmet is on, going down to their hips. They are tied at the end with metal rings. It is likely that these hair extensions are a part of the headpiece.
They typically walk upright, but sometimes will run on all fours if they are trying to move quickly.
Most of the time Nanachi is cool and reserved, keeping their distance emotionally and physically. Their attitude often borders on being sarcastic and even cynical, however behind this mask, Nanachi hides a kind and gentle soul, capable of deep compassion and selfless devotion. They are also quite bashful when complimented, seen in their reaction to being called "fluffy". They also express discomfort at being petted, especially by Reg.
Dreadful Experimentation Flashback Arc
Nanachi was born in the Far North region of Sereni, lost their family and home at a young age, and was taken to the Abyss by the infamous white whistle Bondrewd, along with many other children.
Bondrewd was experimenting with ways to negate the curse of the abyss, using children as his test subjects. While in the Abyss, Nanachi meets Mitty, another child taken by Bondrewd, and the two became close friends. Eventually, the number of children decreased, until finally Mitty was chosen to be experimented on and was led out by Bondrewd. Worried for Mitty, Nanachi followed, and soon found her trapped in one of two connected capsules.
Walking in at that moment, Bondrewd then decided to use the two as test subjects together because of their strong relationship, as previous experiments with humans and animals had not been effective. Nanachi was then forced into the other capsule, lowered to the 6th layer, and then quickly brought back up. The capsules were designed to transfer the curse onto only one subject, Mitty, leaving the other potentially unaffected. Both survived and became Narehate as a result, but Nanachi retained their humanity and mind, as the majority of the curse was transferred to Mitty.
Nanachi, in their new Narehate form, continued to work for Bondrewd at Idofront, helping him to create Cartridges. Unable to bear the horrible experimentation Mitty was subjected to any longer, Nanachi escaped Idofront with Mitty on their back. The two traveled up to the 4th layer, where Nanachi found a spot away from the Abyss' vertical shaft where the force field was not present, and constructed a hideout there. Nanachi lived peacefully with Mitty in the fourth layer for some time. Sometimes delvers would pass through the area, and fearing that word of them may get out, Nanachi was careful to not reveal themself, and instead would watch from a safe distance. Occasionally, when a delver was wounded beyond help, Nanachi would take them in and experiment on them, hoping to find a way to kill Mitty. The bodies of these delvers are buried in a graveyard behind their hut.
Poison and Soul Liberation Arc
During Riko's and Reg's descent to the 4th layer Nanachi observes them. After the battle against the Orb Piercer, they reveal themself to Reg, due to seeing him crying over Riko's body. Because the two's relationship remind Nanachi of their relationship with Mitty, Nanachi decides to aid them. During their stay Reg demonstrates the power of his Incinerator, which is similar to Bondrewd's relic Sparagmos; the only thing that had been able to permanently injure Mitty. Seeing the opportunity, Nanachi asks Reg to kill Mitty, releasing her from more suffering, to which he reluctantly agrees. After Mitty's soul was released, Nanachi bursts out in tears and mourns the loss of their friend, while being comforted by Reg. Nanachi decides to join Riko and Reg on their journey to the bottom of the Abyss.
After preparations, the group embarks from Nanachi's hideout, reaching the field of Eternal Fortunes. There they encounter one of Bondrewd's Umbra Hands. A brief exchange follows, in which the Praying Hand tells them that Bondrewd is expecting them. Then the three of them reach Bondrewd's base, Idofront; a girl, Prushka, approaches them and asks if they are her father's guests. A few moments later Bondrewd arrives, greets the trio and informs them that entrance into the 6th layer is only possible with a White Whistle. He invites them to stay a night and Prushka gives them a tour of the base.
During the night, Nanachi seeks out Bondrewd to question him about Prushka. After a short exchange Bondrewd asks Nanachi to become his assistant again. Nanachi agrees under the condition to let Riko and Reg advance safely into the 6th layer, however Bondrewd can't agree to this due to Reg being an existence he wants to study. Nanachi finds Reg as the Umbra Hands experiment on him and have already cut off is arm. Moments later Prushka and Riko join the scene and 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. The trio, together with Prushka, escapes outside the Idofront and tries to escape in a boat. Only Prushka stays back, because she wants to convince Bondrewd to return Reg's arm.
Shortly afterwards Reg, Nanachi and Riko are confronted by Bondrewd and his Umbra Hands again, however they have been let into a trap by the trio and are attacked by a Stingerhead. Only Bondrewd survives the attack with his Sparagmos, but is dispatched by a clever strategy of Nanachi and Reg resulting in him being exposed to the Curse as well 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 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 Idofront whenever they are ready. This leaves Nanachi in an traumatized state, but they quickly recover after 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 their "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 between Reg and Bondrewd, Nanachi acts as Reg's support viva communicator. While they fight Bondrewd reveals that he turned Prushka into a cartridge.
After Bondrewd's defeat, resulting him to be cut in half, Nanachi approaches his upper half and speaks to him for the final time. They tell him that they are going to destroy Zoaholic and any reminding quipment, so his dream will end there. Bondrewd tells them he doesn't mind, as for is new dream is that Nanachi will have a fullfilling adventure and passes away. Nanachi makes a harness so Riko can wear Prushka's stone, which came out of her cartridge, 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.
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 Majikajya and tells them that it only took Prushka's stone to get it worked on by a jeweler in order to make it into its finalized form. While they are waiting, Majikajya explains a few things about the village, Ilblu, and brings them to a market. Due to an accident, Meinya is injured and the group witnesses the village's ritual to balance value. 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. Majikajya tags along with Nanachi and reveals in a conversation about value between them that one of the Three Sages of the village, Belafu, is in possession of the supposed-to-be-dead Mitty. Nanachi asks Majikajya to take them to the sage. Later on, Riko visits the sage since she has been informed to find Nanachi with him. Riko finds Nanachi and Mitty with Belafu, and he 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 Belafu extends his feelers to drink from Mitty.
Belafu tells Riko that Nanachi offered themself up to him in exchange for ownership of Mitty so that Belafu 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.
Nanachi has demonstrated advanced tracking and stalking skills; when Reg and Riko first entered the Abyss' 4th Layer, although Reg could tell that Nanachi was nearby, he was unable to pinpoint their location. They were capable of tracking Reg and Riko throughout their journey in the 4th layer, continuing to remain hidden, until they voluntarily revealed themself upon seeing Reg scream when he thought that Riko had died.
On top of top-notch tracking and stalking skills, since becoming a Narehate, Nanachi has been able to see the flow of the Curse of the Abyss — a mysterious force that is behind the ailments human beings suffers upon attempting to ascend from the Abyss. Thus, they are capable of avoiding it.
Aside from their skills granted to them by their Narehate nature, Nanachi has been shown to be deeply knowledgeable about the flora and fauna within the abyss; they are capable of determining what is edible, as well as if something has any medicinal properties. Their time spent in Idofront has also lead to them knowing how to perform some complex surgeries. Using this knowledge, Nanachi has tended to myriads of maladies that delvers may suffer from, such as being able to splint broken arms, suture open wounds, and even creating an antidote for Orb Piercer venom. Many of the curative methods and medicines they use are unknown even to delvers, who are often thought of to be the most knowledgeable of the Abyss.
Nanachi is also shown to be artistically talented, having demonstrated excellent ability in drawing. They have drawn pictures of themself, Mitty, Reg, and Riko; a representation of how the curse works for Reg; and accurate depictions of the things they required Reg to fetch in order to aid them in healing Riko's arm.
- Nanachi is generally presumed to be female, based upon their feminine appearance. However, their gender and sex have never been explicitly stated within the series itself. The only gender referent used by Nanachi is the pronouns that they used to refer to themself with. When talking about themself Nanachi uses the pronoun oira (おいら, which is similar to ore (おれ) but more casual. Evokes a person with a rural background, a "country bumpkin"), which has a masculine connotation to it. The creator of Made in Abyss, Akihito Tsukushi, commented on Nanachi's sex on Twitter, stating: "the sex of Nanachi is unknown. Let's imagine :)." The official English translator of Made in Abyss has also chosen to use gender neutral pronouns. Given that the changes made to survivors of the curse are random, it's possible that Nanachi may not actually have a gender at all.
- Occasionally there are extra pages at the end of chapters that give more detailed descriptions of the creatures and relics seen; Nanachi often shows up on these pages giving their own insight on the subject. These small bits are called "Nanachi's Trivia."
- Nanachi has an "irresistible fragrance". In particular, the base of their tail smells really good. They are also really fluffy. This is an interesting parallel between their former human self, who was smelly and repulsive to others.
- Their age is likely older than appearance suggests.
- When signing their name, they always draw a picture of their face with the characters for "Nanachi" underneath.
- Nanachi makes a brief cameo on Pop Team Epic's episode 2 when (s)he appears on one of Popuko and Pipimi's "Ridiculous Fortunes." It says "Good Luck, Nanachi is cute!"