Nana Rin is a Hong Kong mage and the eldest Rin sister alongside siblings Nana and Mimi. She enters the Granbelm tournament driven by a desire to reunite her family, a mission fueled by her mother Lin Fen Fen's abandonment. Though an adult, her childlike physique results in enrollment at a middle school, where she forges a bond with Kibō Kohinata.

Initially stubborn and emotionally distant, Nana Rin maintains an aloof demeanor as armor against familial wounds. She prizes fair combat, openly rejecting underhanded tactics; this principle contributes directly to her tournament defeat. Eliminated by Mangetsu Kohinata, she undergoes significant growth, becoming more open and supportive. She acknowledges Kibō as her best friend and aids Mangetsu and Shingetsu Ernesta Fukami by monitoring later battles.

Her investigation proves vital: examining erased participants like Anna Fugo leads her to uncover the Magiaconatus's manipulations and Mangetsu's artificial nature as its creation. In combat, she wields talismans for tracking and concealment, paired with sharp data analysis. Enhanced sensory abilities let her detect distant magical signatures and visualize opponents during fights, augmented by martial arts skill.

Her Armanox, Ji Guang Long, uniquely adopts a stealthy spaceship form for long-range engagements before shifting into a colossal mecha for close combat. Its noted inability to fly is speculated to stem from her fear of heights. Her relationships center on her sisters, Kibō, and fellow Granbelm participants, marking a journey from isolation to active camaraderie after the tournament.