Aizawa Haruki, 16 years old, is in his 2nd year of high school, and likes to live efficiently. One day during summer vacation, a girl, Aizawa Himari, suddenly appears, calling him 'Onii-chan' and claiming that she's his little sister. As it turns out, Haruki's father recently remarried, and his new wife brought a daughter with her. However, since both of their parents are overseas, it'll only be the two of them living under the same roof. And for some reason, Himari seems … read more