Hachimitsu Academy, once an all-girls school, has become co-ed, and teen Kiyoshi is one of five boys to enroll. When he is caught peeping, Kiyoshi is sent to the schools prison, where his punishment is carried out.

Ken Kaneki is a bookworm college student who meets a girl names Rize at a cafe he frequents. They're the same age and have the same interests, so they quickly become close. Little does Kaneki know that Rize is a ghoul - a kind of monster that lives by hunting and devouring human flesh. When part of her special organ - "the red child" - is transplanted into Kaneki, he becomes a ghoul himself, trapped in a warped world where humans are not the top of the food chain.