Aion (碧海のAiON Hekikai no Aiōn?, literally meaning "Aion of Green Sea") is a Japanese manga series written and illustrated by Yuna Kagesaki. The series was published in Japan by Fujimi Shobo and serialized in Monthly Dragon Age magazine. The manga has been distributed in English by Tokyopop. The story is about an immortal girl, Seine Miyazaki, and an orphan boy, Tatsuya Tsugawa, who gets involved with her.