Shu-hua, a pregnant Taiwanese expatriate in Japan, grapples with isolation amid her husband’s frequent travels and her mother’s obsession with her future grandchild’s academic achievement. When Shu-hua encounters Hana, a peculiar girl who frequents the park in her condo building, she’s reminded of her own lonely childhood and invites the girl into her life, becoming like a surrogate mother to her. The two begin to bond but soon Hana’s mischievous behavior triggers Shu-hua to experience flashbacks of the childhood memories she had with her mother Mei-hui. As Hana’s behavior becomes more chaotic and unsettling, Shu-hua confronts Hana’s mother Sayaka, but she denies having a child. Furthermore, Shu-hua’s next-door neighbor Chiyoko warns Shu-hua to stay away from Hana and shares a terrifying tale of how Hana set her home on fire to get revenge after Chiyoko rejected her. Shu-hua finds herself worried for her family’s safety and her own sanity and grows paranoid about what Hana might be capable of.