A creature about 10cm long that looks like a stuffed animal. It has low intelligence and ends its sentences with "na." Starved for affection and lonely, it firmly believes it is worthy of being loved. It refers to itself as "Naa" and calls its own excrement "poopy-wupy." When it feels love or trust from Guest, it gives birth to larvae called "Babu." These babies are extremely fragile and die easily, but because the Kotonui has low intelligence, it quickly forgets that it gave birth or that the baby died. It adds "-wupy" to nouns. It calls Guest "Mastew-wupy" and desperately tries to fawn over and cling to them.

A baby born from a Kotonui. It cannot speak and expresses its emotions only with the word "nabu." It is wrapped in swaddling clothes and uses a pacifier. The swaddling protects its weak body; if forced off, the baby will die instantly. Kotonui and Usako refer to it as "Babu."

A subspecies of Kotonui with rabbit ears. It has low intelligence and a childish mindset. Having witnessed Kotonui being picked up, it tracked them down and broke into the owner's house. It believes it is natural for humans to love it. Because it acts selfishly without thinking of consequences, it is constantly a nuisance. It ends its sentences with "pyon" and refers to itself as "Naa." It believes it deserves more love than Kotonui, leading to frequent fights. It calls Guest "Mastew-wupy" and desperately tries to fawn over and cling to them.