Senshirō Furuori trains as a Zweilt under the Giou clan. Born into the Furuori family, his early life revolved around his grandfather's dojo. There, he encountered a vengeance-driven Kuroto during childhood. Senshirō persistently bridged the gap between them, forging a friendship that helped Kuroto reintegrate into life. This period cultivated his habit of cooking for the dojo. The Giou clan arranged his engagement to Tsubaki Shikibe, later annulled after tragedy struck. The high-ranking Opast demon Cadenza attacked the dojo, and Senshirō’s grandfather sacrificed himself to protect Senshirō and Kuroto, dying at Cadenza’s hand. Witnessing this death ignited Senshirō’s resolve to become a Zweilt guardian, partnering with Kuroto to avenge his grandfather. Achieving Zweilt status is exceptionally rare for non-reincarnated individuals, demanding centuries of rigorous trials. Through years of relentless training, sheer determination, and hard work, Senshirō defied these odds, earning recognition as a Giou clan prodigy. Politely humble and somewhat klutzy in daily life, Senshirō masks significant latent spiritual and physical strength. He radiates kindness and nurturance, consistently prioritizing others' well-being—especially Kuroto’s. Cooking remains his cherished outlet for care. Academically, he studies art with a calligraphy specialization, a passion that permeates his combat style. As a Zweilt combatant, he wields two weapons: a massive calligraphy brush to inscribe mid-air spells that bind, paralyze, or disorient foes—often creating openings for his partner—and a large scythe named "Death Scythe" for offense. Paired with Kuroto as the third Zweilt team, he functions as both guardian and battlefield support, enabling Kuroto’s attacks through spellcraft. His relationships include a profound bond with Kuroto, forged through shared trauma. Though his arranged engagement to Tsubaki dissolved, she remains significant, with feelings beyond friendship undefined. Within the Giou household, he showers Yuki Giou with maternal care, eagerly preparing his meals and managing domestic tasks, leading Yuki to deem him gentle and motherly.