Doug Funnie experiences common predicaments while attending school in his new hometown of Bluffington, Virginia.

The story begins with Keita Suminoe, a male third-year junior-high school student studying for his high school entrance exams. He is living in a home with his older twin stepsisters, Ako and Riko, who share no blood relation to him, and they help him prepare for his exams. Even though he initially dislikes himself for it, he begins to become attracted to his two step-sisters, and his two parents encourage him to eventually get married to one of them.

Girls from all over the world gather at IS Academy to learn how to become IS pilots. However, since Ichika can somehow pilot the IS even though he is male, he was forced to attend IS Academy as the only male in this school.

15-year-old Yoko, a young girl who is constantly tormented by her self-centered and devilish older sister Makiko, who works for a government office after having graduated from a famous university. But despite her ill nature, Makiko's actions tend to somehow make things better for those around her, causing others to praise her as an "ally of justice."

In Alexandria, a girl goes out to work in trade in order to provide for her siblings and afford their education, an endeavor that leaves her exposed to a lot of difficulties as she tries to keep the family together.