Hyojoo lives taking care of her younger brother, a theater actor. One day he goes missing, and she meets Wonyoung, a believer of the cult 'Soulism', which her younger brother had belonged to. Hyojoo goes with Wonyoung to Ganghwa-do, where her brother might be to see the sea. Before her acknowledgement, Hyojoo starts to trust and rely on Wonyoung.