his father's mistress, hoshino akari.

Masakazu works at his father's office to take over the company in the future. Masakazu had a strong resentment against his father, who always walked with different women. One day, Masakazu found his father's notebook with a date written with a woman, and when he visited the lover's house where his father went, he appeared because he was working at the same office. Masakazu persuaded him to break up with his father while he was jealous of a completely different atmosphere from the workplace, but from there he learned the complicated relationship between men and women.