When a devastating natural disaster leaves 17-year-old run-away Yui and 8-year-old orphan Hiyori without a home, they are taken in by Kiwa, a strange old woman who offers to let them stay in an abandoned yet suspiciously well-kept house overlooking the sea, known as a Mayoiga: a legendary house, said to look after lost travelers. Despite Yui’s hesitation to trust anyone and Hiyori’s inability to speak, they begin to form a sisterly bond that allows them to find comfort in the Mayoiga and embrace Kiwa’s hospitality. However, when a menacing entity is accidentally released and threatens their new home, the three must face their fears to save it.