MOON-051 - At PM23:00 while the husband is asleep, a glamorous female teacher, Onosaka Yuika, brings in a male student (M Nan-kun) nightly, engages in sexual acts, and skillfully subdues him.

A beautiful female teacher invites favored students home under the guise of 'extra tutoring'. Enticed by her popularity, the student knocks on the door with anticipation. However, on nights when her husband is asleep, she reveals her true nature with a strange smile. In the basement, even when the student reaches their limit, they are treated as a sexual tool until she is satisfied – a secret time hidden behind a peaceful daily life, unknown to anyone.