Seika (星華, Seika) is Seiya's older sister, whom he has not seen in years. After he was taken away, she wandered the world looking for him. It has long been implied that Marin (Seiya's mentor) could have in fact been Seika, and some characters, including Seiya, thought it could be true (Marin and Seika even have the same physical characteristics: same age, same birthdate, same height, same birth place). Marin even has a brother she lost and was looking for. But Seika appeared as an independent character in the Hades chapter, completely amnesiac. Marin finds Seika and brought her along.