Set in Tokyo's Sakura Motomachi during the 1960s, the film follows the intertwined friendships of three children as they encounter yo-kai. Shin, a boy living in poverty, finds joy until his mother - his only family - passes away. Itsuki, who has also lost his elder sister, helps Shin through his grief, and the two boys, along with Tae, who can see yo-kai, develop a strong bond. Together with Suu-san, Shin's guardian spirit - a Nekomata cat - and other yo-kai, this newfound family rediscovers the importance of having loved ones. However, a cryptic incident surfaces, forcing the group to confront a jarring truth.