Ryou Saeki, a dedicated female teacher striving to be a role model, begins to feel a piercing emptiness in her chest. Day after day, she grows restless, sensing that something vital is missing. Then, through an encounter with a student, she finds herself stepping into a hotel. There, she meets a completely new version of herself—someone different from the person she's always been. As she teaches a younger boy about sex, the void in her heart slowly starts to fill.