Tenjirō Kirinji holds the position of First Officer within the Zero Division, the Royal Guard, bearing the titles "Hot Spring Demon" and "Divine General of the East." His paramount duty is the protection of the Soul King and the Royal Palace, taking precedence over any obligations to the Soul Society's Gotei 13. Kirinji cuts a distinctive figure: tall and lean, with black hair styled into an exceptionally large pompadour and tapered sideburns. His wide eyes tilt inward, featuring pinprick pupils. He is often seen chewing on a small stick. His attire consists of a modified Shihakushō: a sleeveless, cropped white jacket emblazoned with the Royal Guard emblem, worn open to reveal his chest, paired with black hakama, a yellow haramaki around his waist, and waraji sandals worn without socks. His personality is boisterous and condescending. He frequently speaks down to Gotei 13 members, including captains, as if addressing children. This patronizing attitude often results in physical discipline from his fellow Royal Guard, typically sharp blows to the head. Kirinji exhibits confidence in his combat prowess, confronting Yhwach directly during the invasion of the Soul King Palace and stating he only engages when victory seems possible. Before ascending to the Royal Guard, Kirinji served as a Gotei 13 captain. His promotion stemmed from his invention of Kaidō, the foundational healing Kidō techniques of the Soul Society. He personally instructed Retsu Unohana in these arts, who later became Soul Society's greatest healer. The Soul King recognized this pivotal contribution, elevating Kirinji to the Royal Guard. During the Thousand-Year Blood War, following Captain-Commander Yamamoto's death, Kirinji returned to the Soul Society. He dismissed Captain Suì-Fēng's criticisms regarding the Royal Guard's absence, emphasizing their exclusive mandate to protect the Soul King. He transported critically injured Shinigami, including Byakuya Kuchiki, Renji Abarai, and Rukia Kuchiki, to the Royal Palace, asserting his healing methods surpassed Unohana's. In his Kirinden facility, he healed Ichigo Kurosaki and others using two specialized hot springs: the White Bone Hell, which expelled damaged Reiatsu and blood through accelerated healing (requiring protective suits against erosion), and the Blood Pond Hell, which replenished lost blood. His unorthodox method to confirm recovery involved striking patients; survival meant they were healed. He expressed admiration for Ichigo's combat reflexes and noted Byakuya's exceptional endurance. When the Wandenreich invaded the Soul King Palace, Kirinji swiftly eliminated Quincy Soldat summoned by Jugram Haschwalth. He then engaged Yhwach directly, releasing his Zanpakutō, Kinpika, and wielding his hot spring water offensively. His attacks failed to land due to interference from Sternritter Nianzol Weizol's ability, "The Wind." Later, he assisted Ōetsu Nimaiya by replacing his poisoned blood with Blood Pond Hell water, enabling Nimaiya to defeat Askin Nakk Le Vaar. Kirinji also attempted to block Lille Barro's attack on Nimaiya using his hot spring water, though Lille's "The X-Axis" ability rendered this ineffective. Ultimately incapacitated by Askin, Kirinji sacrificed his life alongside Nimaiya and Kirio Hikifune to break the Blood Oath's Seal, allowing Senjumaru Shutara to activate her Bankai. Kirinji's combat abilities include immense spiritual power and mastery of Shunpo, earning him the historical epithet "Lightning-Fast Tenjirō" for speed surpassing even Suì-Fēng's. He demonstrates enhanced strength, capable of hurling opponents considerable distances, and durability allowing him to withstand his hot springs unprotected. His Zanpakutō, Kinpika, in its sealed state resembles a small curved blade on a wooden pole. Its Shikai release command, "Flash from Illuminating Heaven," generates blinding golden light, though its full abilities remain unspecified. He manipulates the temperature and movement of his hot spring water for offensive burns or healing. As a Royal Guard member, he possesses the Ōken, enabling travel to and from the Soul King Palace and granting access to others. His inventions define his legacy: the Kaidō healing arts, the White Bone Hell for purging damaged Reiatsu, and the Blood Pond Hell for blood replenishment. These innovations solidified his status as Soul Society's foremost healer.