Summary
Jin Koishikawa is Miki’s father and works as an accountant at a bank. After ending his relationship with his former girlfriend Chiyako, he supported Rumi through her own breakup with her boyfriend Youji, and the two eventually married. The couple relocated to England, where Miki was born, before returning to Japan. Years later, they run into Chiyako and Youji again, leading to an arrangement where the two couples swap spouses.
