Free-spirited schoolgirl Yui one day meets a female teacher on a whim, and in that instant, their hearts plunge into a forbidden romance. Craving to confirm their feelings, they passionately desire each other, their lust escalating intensely. But when the teacher's lover appears, their relationship begins to crumble amid tangled jealousy and desire. Amid this whirlpool of complex emotions, Yui finally finds the chance to reflect on her own true feelings.