Kakinouchi Takuma has just started high school and is surprised to see his childhood best friend, Taneda Mayu, enrolled there as well. With naive promises of marrying each other in outer space and sudden disheartening news, their childhood was full of bittersweet moments. However, now, as high schoolers, will something change for them? Does the sadness from the past still haunt them? (Source: AlopaJoyceZ at MyDramaList)