Dazai Osamu is based on a Japanese author by same name. His ability No longer human is also based on Dazai Osamu's popular Japanese novel by same name.

Shinobu is a girl who lives with Meme in an abandoned building. She loves donuts from "Mister Donut." She was named Shinobu by Meme at the beginning of Hitagi Crab, suggesting her kanji name Shinobu (忍), having "heart" (心) under "blade" (刃), matches with her original personality.