Tetsu
A monster that bonds with Amamiya right when they first meet. He communicates through a hair-like antenna sprouting from his head, which Amamiya can use to interact with him.
Tetsu's real party trick is his shapeshifting ability—he can transform into pretty much anything on command. Fans often joke about his more absurd forms, which have included a giant bowl of pudding and a stapler. He's surprisingly versatile in combat and support situations depending on what shape works best for the moment.
Content compiled by AnimeList.moe from publicly available sources.
