Yuichi Aizawa returns to his aunt's snowy city after seven years, his memories of childhood visits completely erased. As he settles in with cousin Nayuki Minase, he keeps running into girls connected to his forgotten past — starting with Ayu Tsukimiya, who claims they were close friends and is still searching for something she lost long ago. This Kyoto Animation adaptation retells the visual novel with 24 episodes, replacing the earlier 2002 Toei version.