Kosuke Kumagaya and Natsume Tonai, both 11 years old, are childhood friends who grew up like siblings. The relationship between the two began to be strained after the death of Kosuke's grandfather, Yasuji. One day during the summer vacation, Kosuke and his classmates, Taishi, Yuzuru, Reina, and Juri, sneak into the "ghost housing complex" that has been slated for demolition. The housing complex was also a house full of memories where Kosuke and Natsume grew up. Kosuke unexpectedly encounters