On the first day of the second semester of middle school 2nd grade, Shiyumi came across a hidden cigarette scene of a classmate boy, Chizaki, in the backyard of the school. Honor student, popular person (and a childhood friend Mari's crush), but unexpectedly messing around with her, she can say that?? Chizaki, who can't see anything forever, she's starting to worry about him… Chizaki, who are you─?