When two magical sisters discover a mysterious ring, they make their way out of the sea to find the rightful owner, unknowingly setting off chaos.
S01:E01 - Heart of the Sea, Heart of the Sky
Marin and Urin decide to return a ring its owner. But while the surface holds many wonders, it also hides a great darkness...
S01:E02 - Heart of the Ring, Heart of the Priestess
Something dark and sinister was released from that coffin. His name is Matsumoto, and he knows the truth behind what's happening.
S01:E03 - Hearts Grow Closer
Since Marin has a newfound duty as Priestess of the Sea, she'll need a place to stay. What better place than Kanon's house?
S01:E04 - The Heart That Is Tested
Matsumoto gives Kanon a treasure map. If she can find the treasure hidden on Kagero Island, it will grant her the pure heart she seeks!
S01:E05 - The Heart That Obscures the Light
A solar eclipse is coming, but while it should be a happy event, Matsumoto has a dire warning.
S01:E06 - The Heart That Succumbs
Everything is falling apart. Urin is missing... The sky is black... Marin can't shake the cold grip on her heart...
S01:E07 - The Heart That Grows Distant
Urin has returned to the sea, but something's not right. Ever since the eclipse, Urin has been cold and distant...
S01:E08 - Hearts That Need One Another
Marin and Urin used to be inseparable. But now, Urin is walled off and locked away, beyond Marin's reach.
S01:E09 - The Heart That Loves
Marin is so filled with doubt and grief, that she can no longer become the Priestess of the Sea.
S01:E10 - The Heart That Falls Silent
Even though Marin and Kanon have gotten stronger, they're no match for the darkness seeping its way into everyone's hearts.
S01:E11 - Heart of Light, Heart of Darkness
Not only are the people on land under Sedna's control, but so are the people of the sea – including Warin and Sam!
S01:E12 - Heart of the Island, Heart of the People
The truth behind Sedna's identity has been revealed, but it's too late.
S01:E13 - Faithful Hearts
A year has passed, and Kanon returns to spend the summer on Amamiko Island.