Taichi, the son, was raised constantly receiving love from his mother, Itsuki Sara. However, he gradually began to harbor romantic feelings for her as a woman. He decided to keep these emotions hidden forever. After their father left home to be with a mistress, Sara often lamented, speaking of memories with her husband. Witnessing her sorrow, Taichi grew jealous of his father and began treating Sara with coldness—a reflection of his suppressed love. One day, seeing Sara deeply depressed, Taichi resolved to take her on a hot spring trip, leaving work behind to comfort her.