Who would have thought a simple ring could cause so much trouble? Marin and Urin are sea folk, people who live in a peaceful underwater world surrounded by bright fish and colorful coral. But one day, a beautiful ring falls from the sky - that dangerous place above the water - and the two girls decide to return the lovely trinket to it's owner. While the surface world holds amazing wonders for the pair, it also hides a great darkness a darkness that Urin accidentally unleashes when she opens a stone box at a local shrine. Now it's up to Marin, Urin, and their new friend Kanon to set things right again before that darkness swallows the entire world! Directed by Junichi Sato (ARIA, Tamayura, Sailor Moon), Animation by Hal Film Maker (ARIA). Contains the complete 13 episode TV series. Bonus features: Marin's What is This? episodes 1-4, Web Promos, Commercials, Promotional Video, Clean Opening and Ending. Audio: Japanese. Subtitles: English subtitles/on-screen translations.