Reina hails from the Land of Shura, alongside her older brother Sōga. She shares a significant history as a childhood friend of Raoh from their homeland. Before Raoh departed Shura, he made a pivotal promise to Reina: vowing to return and liberate their land from suffering. This commitment forms the bedrock of her unwavering loyalty and motivations.
Reina masters the twin-sword fighting style Nichigetsu Sōtō (Twin Blades of Sun and Moon), earning her the epithet "Reina of the Twin Blades." Her combat prowess secured her the formal role as Captain of the King of Fists Royal Guard (拳王親衛隊隊長, Ken'ō Shin'eitai Taichō). In this position, she commands Raoh's cavalry forces and serves directly under his authority, her allegiance steadfastly aligned with his ambitions and leadership.
Beyond the film *Raoh Den Gekitou no Shou*, Reina features in expanded franchise narratives. She appears in the spinoff *Ten no Haoh* (The Conquering King of the Heavens: Fist of the North Star Raoh's Story), serialized in Weekly Comic Bunch, which focuses on Raoh’s saga. This series further explores her connection to Sōga and her role within Raoh’s inner circle across 42 chapters and a two-part epilogue.
Her visual design for the Shin Kyūseishu Densetsu film series was created by manga artist Tsukasa Hōjō, contributing to her distinct aesthetic within the animated adaptations.