Marin and her sister Urin live in the sea. One day they find a ring fallen into the sea. They get out of the sea and meet a girl Kanon, the owner of the ring. Kanon tells them she doesn't want the ring anymore because it was given by her boyfriend whom she just broke up with, and she throws it into the forest. Marin thinks Kanon is still in love with him and looks for the ring with her sister. But Urin accidentally breaks a seal near a shrine...

Episode 1 - Heart of the Sea, Heart of the Sky

Episode 2 - Heart of the Ring, Heart of the Priestess

Episode 3 - Hearts Grow Closer

Episode 4 - The Heart that is Tested

Episode 5 - The Heart that Obscures the Light

Episode 6 - The Heart that Succumbs

Episode 7 - The Heart that Grows Distant

Episode 8 - Hearts that Need One Another

Episode 9 - The Heart that Loves

Episode 10 - The Heart that Falls Silent

Episode 11 - Heart of Light, Heart of Darkness

Episode 12 - Heart of the Island, Heart of the People

Episode 13 - Faithful Hearts

ZEXCS

Umi Monogatari