Hitomi, who has retired from her teaching career and is now working as a cram school instructor, is busy living alone and is looking for a housekeeper. One day, Yui, who was looking for work after her husband was laid off and the house was sold, sees an ad for a live-in housekeeper and comes to visit. Yui's visit causes Hitomi's sanity to crumble. Yui is the spitting image of a former student whom Hitomi secretly had feelings for during her time as a teacher and who passed away. Hitomi sneaks into the bedroom where Yui, who knows nothing about it, is sleeping drenched in sweat...