Tsubaki starts off her brand-new high school life the right way—by visiting an onsen! In the bath, she has a chance encounter with a beautiful black-haired goddess."Won't you come to an onsen with me?" Pursuing her with fervor, is it possible to have a relationship with someone before you even become friends? This is the story of two girls who love the onsen and the ups-and-downs of their hot spring days.
The stage is a modern school that fosters female officers, "Girl's Only Army School".A girl, Indou Shinobu, who came out from the countryside, meets Kagami a high-class senior student.Contrary to her high-handed attitude, Kagami occasionally shows kindness to Indou.