The wife lives with her husband and father-in-law. She was drawn to her husband's seriousness and married him, but he is always working, leading to a sexless marriage. During this time, she finds herself attracted to her kind father-in-law. One day, from a news topic, she learns that her father-in-law and husband have the same blood type. 'If they have the same blood type... but...' She hesitates but still has an immoral thought. Furthermore, when her husband confesses his dislike for children and she catches her father-in-law masturbating with her underwear, she makes up her mind to seduce him and start a relationship. After that, like a kite cut from its string, they repeatedly have affairs, ultimately leading to... incestuous, forbidden pregnancy intercourse.
