Birthday-Death Disease

Birthday-Death Disease (にぬ) is a mysterious disease that occurs on the surface around The Abyss. A person falls horribly ill on their birthday, and by the end of the day they will have died, no matter what medical treatment they receive.

The disease was initially thought to be a rumor. Prior to Riko and Reg departing into the Abyss, eight children from the West District of Orth had already died on their birthdays. Later, Laffi recounts that a number of her regular customers had died on their birthdays and Jiruo explains to Mio that five orphans had also passed away on their birthdays, with many more such cases throughout the community. It is a subject of great worry among the citizens of Orth.

The only known survivor thus far is Kiyui, who recovered in mere minutes, after he was taken out of the Abyss' vicinity onto the Caravan Fleet by Mio.

It is thought to be the cause of all the 2,000 year old Praying Skeletons found around a Burial Tower in the 1st Layer. Underneath the tower is a tomb with even more Praying Skeletons, dating back 4,000 years; leading into a secondary tomb with skeletons up to 6,000 years old.

Though the reason for these mass deaths is unclear, Birthday-Death Disease seems to be a likely candidate. The cause of the disease is unknown, but is thought to be linked to the Abyss itself. Those who don't leave the Abyss when it goes around can only pray to be spared, thus it is theorized to be the reason for the praying skeletons' postures.

Symptoms
Kiyui was shown to have suffered a fever at the hands of the disease, with Mio noting that she might have otherwise assumed he had been poisoned, but it is unknown if this is the only symptom, thus far.

Known Victims

 * Kiyui
 * Sherumi and Menae (Presumed)