Summary: A world where it has been established that people routinely swing between slightly different parallel worlds... Koyomi Hidaka, who lives with his father following his parents' divorce, meets a girl named Shiori Satou at the research institute where his father works. They both have a little crush on each other, but everything changes when their parents remarry. Koyomi and Shiori, convinced that...

Summary: A world where it has been established that people routinely swing between slightly different parallel worlds... Koyomi Takasaki, who lives with his mother following his parents' divorce, enrolls in a local university prep school. Due to the atmosphere concentrated on studies and his social awkwardness, Koyomi is unable to make friends. One day, he is suddenly approached by his classmate Kazune...