Hiyama Nachi is an ordinary junior high school student who sweats hard at softball and longs for a “tan”. She finds out a serious secret about her classmate, Utsumi-kun. It means that he has a tail. A story of 10 years in which two people communicate with each other, even though they are confused, confused, and hurt by being "different from everyone else." Adapted from the manga series "Okashiratsuki" (尾かしら付き。) by Sahara Mizu (夢花李).