Fuwa Rin, a reserved student, finds himself tutoring the flamboyant and rumored-to-be-promiscuous Asukai Ena. After helping her pass her exams, Ena invites Rin to her room for a "reward," leading to an intimate encounter where she reveals her true, inexperienced self and her genuine feelings for him. Bound by their shared first experience, the unlikely pair discovers a mutual affection that changes Rin's quiet school life forever.