my father's mistress, my wife.

Shinji came to his father Ryuichi's house where he manages a company in Tokyo on vacation and is assigned as a single person. When he is surprised by his father's arranged room, Ryuichi brings Hikari to his house who was in charge of the company. Sinji sees her making a meal in a familiar way and notices the relationship with her father. Then, when Sinji gently yelled at Hikari who couldn't celebrate Ryuichi's birthday and made him feel lonely alone, he asked Sinji to hold her.