Yui, a high school swim team member, is hopelessly infatuated with her teacher, Himari. Her obsession runs so deep that she steals Himari's panties from the locker room to pleasure herself in secret. One day, she skips practice and boldly invites her teacher to the school infirmary, dressed in a tight competitive swimsuit. What begins as a daring provocation quickly turns into a steamy lesbian encounter. Through deep, wet kisses and relentless teasing, Yui awakens Himari's hidden desires. Puffy nipples and flushed, moist bodies respond to Yui's eager tongue, as the teacher surrenders to the forbidden pleasure of her student's touch. A bittersweet and taboo sapphic story unfolds between teacher and pupil, hidden in the quiet hours after school.