Raira, also known as Laila Seiren, is a fourteen-year-old girl in the anime and manga Hero Tales. She is the daughter of Souei, the head of the Seiryutou, a self-defense group formed largely of former imperial soldiers, and she is raised as the younger sister of the protagonist Taito, although the two are not related by blood. She has dark blue hair and blue eyes and is trained in the martial arts. In daily life she usually carries herself in a way that does not draw attention to her being a girl, but she also has a feminine side, including a longing for the capital and the excitement of city life.

Her personality is spirited and sharp-tongued. She frequently argues with Taito and has never lost one of their quarrels, often affectionately calling him her "stupid brother." Despite this combative exterior, she genuinely cares for him and is the only person who can bring him back to his senses when the power of his star, Hagun, causes him to fly into an uncontrolled rage. She is also resourceful and brave, as seen when she recruits the river captain Koyou to rescue Taito and Ryuukou after they are swept away by floodwaters.

Her motivations are rooted in family loyalty. When the imperial general Keirou slaughters the monks of the Renshouji temple and members of the Seiryutou, then steals the legendary sword Kenkaranpu, Raira joins Taito and the monk Ryuukou on their journey to avenge the fallen and recover the blade. In the story she serves as a companion and emotional anchor for the group, and her presence is especially important for Taito, who tends to act before thinking and relies on her to calm him when his power overwhelms him. She is also the object of affection for the archer Housei, who falls in love with her at first sight and often competes with Taito over her attention.

Her development differs between versions of the story. In the manga, she loses her father Souei during the war, and in her grief she is brainwashed by the sorcerer Shimei, temporarily turning her against Taito and leading her to attempt to kill him before the two eventually reconcile. It is later revealed that she is a descendant of the star-manipulating priestesses of the legendary Xia dynasty. This heritage grants her a special ability that allows her to halt the movements of others, and her earlier feat of stopping Hagun's rampage is what first draws Shimei's interest in her. Her notable abilities therefore include her martial arts skill, her stabilizing influence over Taito, and her inherited power to stop an opponent in their tracks.