Mio lives happily with her husband Masaki in their modest home. One day, Masaki gets promoted to assistant department manager, and Mio's grandmother is able to move into a reputable senior care facility—thanks largely to the help of Nishikawa, Masaki's boss and also Mio's former supervisor. When Masaki brings Nishikawa home and drinks too much, he starts acting aggressively. Taking advantage of the situation, Nishikawa confesses his long-standing love for Mio, threatening Masaki's career and her grandmother's future as he begins to dominate her body.