Zavvi - The Home of Pop Culture Prince Endymion was the Prince of the Earth in the backstory for the series, Sailor Moon. Beloved by all his loyal subjects from his kingdom, Elysion, Prince Endymion was a kind prince who cared for all. After meeting Princess Serenity and falling in love with her, he helped try to defend the Moon Kingdom from Queen Beryl but was murdered along with Princess Serenity. Reincarnated now in present time on Earth, he takes on the form as Mamoru Chiba.