Yotsunoha Makoto Yuki, Nono Nekomiya, Iori Yuzuki and Matsuri Amachi were close friends – until their school closed down. Each would be transferred to a new school, so before the friends parted ways they buried a time capsule under a tree on the grounds of their old school and promise to meet there in three years. Time goes by, and after three years without contact they return to the school, only to find that the contents of the time capsule have been hidden by an old teacher of theirs! While searching the school for clues, memories of their time together begin to surface, and old feelings are reawakened…