At Seiruri Girls School, there are two opposing factions: the "Ruri Gumi," made up of respectable young ladies, and the "Ai Gumi," made up of delinquents with questionable behavior.

Among the Ai-gumi students, Nanase Mitsuki is the one most feared by the Ruri-gumi because of her fierce appearance. Nanase has mixed feelings about her reputation, until one night when she meets a young lady of the Ai-gumi, Yuka Hosho, wandering the streets all alone at night…?

This is a sweet and fleeting love story between two people who can only meet at night.