Ruri inherits the role of Ishigami Village priestess from her mother. As the elder daughter of village chief Kokuyo and sister of Kohaku, her lineage descends from pre-petrification pop star Lillian Weinberg, granting her partial foreign ancestry evident in blonde hair and blue-green eyes. Her appearance features waist-length layered hair and a primitively crafted blue sundress. Battling pneumonia diagnosed at age twelve, village elders predicted her short lifespan. Defying expectations through Kohaku's care and personal resolve, she survived. By fourteen, she memorized the Hundred Tales—oral histories passed through generations—within two years before her mother's death. These tales later proved vital to uncovering village origins. Her priestess duties took precedence, including the tradition of marrying the Grand Bout winner. Recognizing Senku's surname "Ishigami" upon his arrival, Ruri linked him to village founder Byakuya Ishigami, Senku's adoptive father, through the Hundred Tales—which included Senku's story as the 100th tale. Recovering from pneumonia using Senku's antibiotics restored her physical vitality, revealing athleticism matching Kohaku's, seen in sprinting and lifting her sister effortlessly. Her sharp memory and observation skills detected subtle changes, like Kohaku's hairstyle. Ruri actively supported the Kingdom of Science. She aided in crafting manganese batteries for communication devices and produced a sewing needle essential for building a record player. Her knowledge of the Hundred Tales guided Senku to precious metals and clarified the petrification event. She offered emotional support during conflicts, comforting spies during village attacks and delivering Byakuya's final message to Senku at his grave. Deeply devoted to Kohaku's safety, Ruri's romantic interactions with Chrome involved mutual, unspoken affection. Chrome proposed, though depicted as tactless. Ruri exhibited resistance to romantic contexts, experiencing a brief, annulled marriage to Senku and failed romantic moments with Chrome. Throughout various story arcs, Ruri evolved from a frail priestess to an active contributor in rebuilding civilization, balancing religious duties with scientific aid. Her knowledge of oral history and personal resilience positioned her as a key figure connecting the village's past to Senku's scientific efforts.