Miyazawa Yuana

Haruki spends most of his time with friends and fellow classmates Airi and Ayana. All seems well, that is until Airi and Ayana form separate clubs, the Mechanical Science Club and the Chemical Science Club. The two vie for Haruki's attention and hilarious chaos usually follows all attempts to make him join.

Follows the sordid relationship between a stepfather, Atsuki, and his two adolescent stepdaughters, Airi and Marina. The young girls' mother is absent for the most part of the story, presumably due to work, allowing for her new husband to pursue his dirty pleasures in peace.