夜空のすみっこで、[Yozora no Sumikko de,]

あの時、僕は星の形をした鍵で、消せない暗闇を閉じこめたんだ・・・
小学校の教師である星野には、高校時代、憧れていた人がいた。
同じ天文学同好会にいた、ひとつ上の須藤先輩。
その先輩と再会したのは、高校卒業から11年が経った後だった。
生徒の保護者として星野の前に現れた須藤は、星野に告げる。
「おまえとはもう二度と会いたくなかったんだ」と・・・

Hoshino is a timid grade school teacher. Sodou was one year his senior in high school. They meet again for the first time in over a decade and discover that Sodou's son is Hoshino's student. The two of them try to figure out how they feel about each other, and try to remember what it was that had brought them together and ultimately drove them apart in high school. They're both different, but that may not matter as much as how they still feel about each other.