在餘生最後半年，談一場足以撐起一世的戀愛——從小因病足不出戶的櫻井萌，校園是她憧憬的樂園、友情是她渴望的情誼。二八年華青春正盛，萌出落成高閣裡的公主。她決心為自己勇敢一回，踏出城堡、走進高中校園，甚至一生懸命追求絕無僅有的初戀也是一生摯愛。她大膽向同學佐藤日向告白，並約定要在生日當天一同見證能使戀人廝守一生的「草莓月亮」。但在滿月升起之前，萌卻突然失去了蹤影……。

A frail teen girl dreams of watching June's Strawberry Moon with her soulmate on her birthday. After receiving devastating news, she starts high school, finds a boy, and pursues her dream - until she mysteriously disappears.