My husband doesn't know ... A nasty relationship that I can't say even if my mouth is torn. Mai Nanase

The movie revolves around Mai Nanase, who is in a marriage where her husband is often absent due to work, leading to a sense of isolation and unmet desires. She becomes involved in a secret adulterous relationship with another man, which serves as a central plot point. The story explores themes of loneliness, desire, and the complexities of relationships outside the boundaries of traditional marriage.