Ryusei student Koichi lives alone in an apartment, juggling part-time work and prep school. His neighbor, Kanae, moved by his dedication, begins to care for him like a younger brother. One day, after performing poorly on a practice exam, Koichi falls into despair. Kanae comforts him gently, but his emotions only deepen—until he finally pins her down and takes her that night, holding her body close. Knowing Koichi's inherently kind nature, Kanae decides to reignite his motivation by becoming his lover for just one night. Having told her first lie to her husband, how will she get through this single, fateful evening?