"Hey, teacher, why do people betray even those they love?" A lonely girl in search of the "why," first love first love (Uiren Uiko). A kind-hearted female teacher captivated by that girl, self-righteous Aiko Hitoyoshi. Through the encounter of the "teacher" and the "student," their peaceful days become stained with mystery and betrayal, crumbling away fleetingly... Why do people betray others? Why do people fall in love? A youth mystery woven by a new talent, filled with betrayal.