Ruti is Red's younger sister and possessor of the divine blessing of the "Hero," humanity's strongest blessing. She is destined to slay the Demon Lord. This has granted her unimaginable power, yet also inhibits her emotions and very humanity as these are unnecessary for a hero.

She was extremely attached to her big brother and always clung to him when the two were younger. Before he left the party, Red used to dote on his cute sister.

(Source: Yen Press, Official Site)