On a certain island, there are individuals chosen to protect the common folk from creatures emerging from the sea. Elvaone of the chosen onesfulfills this duty, beset with a cursed body that has stopped growing, and in isolation from others. When a boy named Alto learns of Elva's circumstances, he wishes to free Elva from this role. In order to support him, Alto reaches out to Elva, whom no one had dared approach before, and vows to stay by his side forever. After eight years that these two opposites had lived together like master and servant, like a family Elva's body, supposedly only holding out for a few years, has started showing signs of recovery for an unknown reason.