Endo is a tall, slender young man with short, messy, ear-length black hair streaked with blue-green, seafoam green eyes, and a tattoo of black flames on his shoulders, as well as an infinity symbol on his neck. He wears a black tank top under a plaid jacket, black pants, and black and white all-star sneakers. Endo is an easygoing young man who is always shown to have a cheerful and warm nature when around Chika Takiishi. It is later revealed that Endo worships Takiishi as a god.