[Machine Translation] Hidaka Reki, who lives with his father after his parents' divorce, meets a girl named Sato Shiori at the Institute for Imaginary Science, where his father works. The two have a faint infatuation with each other, but everything changes when their parents remarry. Convinced that they will never be together again, Koyomi and Shiori try to jump to a world where they will never be brother and sister, but... But there was no point in a world without her.