Manga by author Yohachi

Atsuki Komiya is a college student who's living alone. Suddenly his sister visits and asks for a favor, which is to take care of his niece Kasane for two weeks. A story about the awkward relationship of these two, the confused Atsuki and the sullen Kasane, living together. Which direction will this story go?

During his youth, Usawa Itsuki often took care of Kameyama Yui, Itsuki's neighbor and several years his junior. When she was in elementary school, Yui declared she would become Itsuki's bride. Years pass, and when they meet again, Itsuki turns out to be a teacher at Yui's high school. Will their relationship develop into something more than just neighbors?