Seiya Kou is a fictional character from the anime series Bishoujo Senshi Sailor Moon, known in English as Pretty Guardian Sailor Moon. Seiya is one of the main characters introduced in the 'Sailor Stars' arc. He is a member of the Three Lights, a popular idol group, and is secretly Sailor Star Fighter, one of the Sailor Starlights. Seiya travels to Earth with his fellow Starlights to search for their princess, Kakyuu. Seiya has a charismatic personality and forms a close bond with Usagi Tsukino, creating an interesting dynamic within the series.