Kotori is a beautiful girl called the "Solitary Ice Princess," respected by everyone in class, while Takumi is a gloomy loner. The two, who never interact in the classroom, engage in acts more intimate than lovers inside Kotori’s room after school. They mess up their clothes only as much as necessary and connect physically in a business-like manner, with no kisses and no conversation. This act is a [Routine] that Kotori created to change the "gloomy" version of herself. One day, she is saved from a predicament by a senior named Ei, a second-year student. Cute, bright, and kind to everyone, Ei is Kotori’s exact ideal. Determined to become like Ei, Kotori continues her "Routine" with Takumi to step toward a new self—a secret relationship where two clumsy people fumble their way toward youth.