Tsumiki is a smart, gentle, and timid honor student. One day, her homeroom teacher suggests she attend remedial classes, promising a reward of going out somewhere together. Tsumiki happily spends time with her teacher, but on their way home, they are confronted by a gang of delinquents who capture the teacher. Trying to protect him, Tsumiki is forced to obey the men's demands. However, it's revealed that the teacher was actually one of the gang members all along. As this unexpected relationship unfolds, the story portrays the clash between Tsumiki's pure feelings and the teacher's true intentions.