The Sea Prince and the Fire Child (1981)

Plot summary: Years after the war between the Children of Water and the Children of Fire, Oceanus, a god of the sea, presents Prince Sirius with the eye of Algarock, thereby putting him in charge of those that dwell under the waves. But when Sirius encounters a beautiful Fire Child named Malta (the daughter of the Queen of Fire), he is lost in love and defies the law that states that Children of Water and Children of Fire must forever remain separate to prevent war from breaking out once more. Sirius and Malta struggle to be together while running into obstacles and suffering great losses along the way. But in the end, are the echoes of history too loud to overcome, or can the two lovers be united and bring peace to the land? Credits to Sanrio No copyright infringement intended