Based on a series of light novels, Kure-nai is about the adventures and misadventures of 16-year-old Shinkurou Kurenai. Shinkurou is an authority in settling disputes between people, and is one day approached by Murasaki Kuhouin, the daughter of a powerful plutocratic family, asking him to be her bodyguard.

Eriko and her friends Yuma and Ayano are excited about entering high school. Their excitement leads to their breaking of the rules when they toured the school before the opening ceremony. They find out their preconceptions about the all female school may not be as true as they had first thought. Despite that, Eriko and her friends are joined by new friends. They aim to get through high school life together.

Eight-year-old Doremi Harukaze aspires to be a user of magic, as she believes it would solve all her problems and help her confess to a boy she liked. One afternoon, she comes upon a magic shop and correctly suspects that the shop owner is a witch. The shop owner becomes a Witch Frog, "greenling", as this happens to witches when their true identities are discovered. In order to retain her original form, the shop owner, Majo Rika, takes Doremi as her apprentice to turn her into a witch. Doremi must take nine witch exams at night to become an official witch; however, she must never let her own identity as a witch be found out or the same fate that befell Majo Rika will happen to her.