My Husband's Brother Who Asked Me To Be His Brush-off Is A Monster! Luna Tsukino's Sister-in-law's Impregnation Runaway NTR Without Noticing That She Is Coming And Without Pulling Out! - Tsukino Luna

The movie revolves around Tsukino Luna, who is in a sexless marriage due to her husband's lack of sexual desire. Her husband's brother comes to visit, and they develop a connection, leading to a romantic and intimate encounter. The story explores themes of marital dissatisfaction, forbidden relationships, and the pursuit of pleasure and intimacy. As the title suggests, the brother is portrayed as a 'monster' who awakens Luna's desires, and the story unfolds as a tale of illicit passion and secrecy.