After losing her parents in a car accident, Okko goes to live with her grandmother, who runs a traditional Japanese inn built on top of an ancient spring said to have healing waters. Okko discovers there are spirits who live there that only she can see; not scary ones, but welcoming ghosts who keep her company and play games. The inn₂s motto is that it welcomes all and rejects none, and it is soon put to the test as a string of new guests challenge Okko's ability to be a gracious host.