Nanachi

Nanachi is a character from Made in Abyss, Nanachi was a formerly human being who survived the ascension of the Abyss' 6th Layer, at the cost of their own humanity. Possessing vast knowledge of the Abyss, its ecosystem, vegetation and even the use of the medicines suggest, Nanachi is currently a part of Riko's party, assisting her in reaching the bottom of the Abyss.

Story
Not much is known about Nanachi's past, they were 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 working on experimenting with ways to negate the curse of the abyss, and using children as his test subjects. While in the Abyss, Nanachi met Mitty, another child taken by Bondrewd, and the two became close friends. Eventually, the numbers 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 hadn't 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. Both survived and became Narehate (a hollow) as a result, but Nanachi retained their humanity, since the curse was transferred to Mitty, while Nanachi received the “blessing“.

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.

Nanachi does reveal themself to Riko and Reg after seeing Reg crying over Riko's body. Because the two's relationship reminded Nanachi of their relationship with Mitty, Nanachi decided to aid them. During their stay Reg demonstrated the power of his Incinerator, which reminded Nanachi of Bondrewd's relic Sparagmos; the only thing that had been able to permanently damage Mitty. Seeing the opportunity, Nanachi asked Reg to kill her, to which he reluctantly agreed. After Mitty's soul was released, Nanachi decided to join Riko and Reg on their journey to the bottom of the Abyss.

Crossover Appearances
2K10 Anime Battle Coliseum

Nanachi is one of the DLC characters from Pack 2.

Trivia

 * 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 use to refer to themselves with. When talking about themself, Nanachi uses the pronoun oira (おいら), which has a masculine connotation to it. 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 elected to use gender neutral pronouns.
 * Nanachi has an "irresistible fragrance". In particular, the base of their tail smells really good.
 * When signing their name, they always draw a picture of their face with the characters for "Nanachi" underneath.
 * 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 makes a brief cameo on Pop Team Epic 's episode 2 when Popuko and Pipimi were checking their fortunes using their cellphones to capture all the screenshots, one of the fortunes says "Good Luck, Nanachi is cute!"