Until I Destroyed My Husband's Other Family.

Kisaragi Minori, who thought she had a happy family with her pure love since they were students and was married to her husband Yudai, was blessed with children, but the story begins when she finds out that her husband Yudai has been cheating on her for 15 years. Minori, who has vowed to take revenge on Yudai, who has another family, and on his lover, Riko Miyake, plots her revenge using Riko's son, Wataru.