Ten years after losing her husband, Reina and her son Shunsuke had been living a quiet life together. One day, Reina brings home a new man and announces her intention to remarry. Shunsuke, raised with deep affection by his mother, is shocked by the sudden turn of events and runs out of the house. However, upon returning home later, he resolves to protect his mother, embracing her tightly and declaring, "I'll be the one to protect you, Mom." A moving story depicting the bond of family and the emotional turmoil over this new development.