Miki's father and an accountant who works at a bank. He married Miki's mother Rumi after breaking up with his old girlfriend Chiyako and helping Rumi over her own break up with her boyfriend Youji. They moved to England and had Miki there, then returned to Japan. Later, he and Rumi reencounter Chiyako and Youji, reach an agreement, and swap spouses

Miki Koishikawa lived a normal life - until her parents tell her they'll get divorced.. She doesn't agree, until she meets Yuu Matsuura... the handsome son of another couple, with whom her parents are switching spouses. They all live together now in an enormous house, and Miki and Yuu find themselves falling in love. They'll have to struggle with their own feelings, other people who want to be with them, and whatever Lady Luck and Fate throws in their ways...<br><br>
(Source: Anime News Network)

[Official Profile](https://www.aoni.co.jp/search/tanaka-hideyuki.html)

Miki’s life was pretty ordinary until the day her parents told her they were swapping spouses with another couple! Thanks to this unconventional arrangement, Miki now has two new stepparents and a hot new stepbrother, Yuu! Miki isn’t exactly thrilled with her new situation, and though Yuu is super cute, he’s also kind of a jerk. Can Miki sort out her complicated feelings for him and come to terms with her new family?
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(Source: Seven Seas Entertainment)

Set 13 years after the original series, the story focuses on Miki and Yuu's little siblings, Rikka and Hajime.

Jin Koishikawa