Ukyo Saionji served as a sonar operator on a Japanese Maritime Self-Defense Force submarine before the global petrification event, his exceptional hearing and rational reasoning proving ideal for the role. Petrified in 2019, he was revived roughly 3,700 years later by Tsukasa Shishio, chosen on Minami's recommendation of his abilities. Joining Tsukasa's Empire of Might, Ukyo rose to become one of its top three commanders alongside Tsukasa and Hyoga. Despite this rank, he privately abhorred Tsukasa's destruction of petrified statues—viewed as murder—yet maintained his position out of survival necessity and fear of direct confrontation, internally condemning his own inaction as cowardice while projecting loyalty. His pacifist nature and aversion to needless bloodshed led him to covertly aid Senku Ishigami's Kingdom of Science after learning Yuzuriha Ogawa repaired broken statues. During the Communications Arc, he intercepted Chrome, Gen, and Magma establishing a telephone system. Though he captured Chrome, he lied to Tsukasa about their activities and later deduced Gen was impersonating Lillian Weinberg over the phone. Using English to conceal their conversation, he revealed his intent to ally with Senku, making his defection conditional on Senku's promise to prevent further loss of life. Once Senku honored this, Ukyo fully committed to the Kingdom of Science and was appointed one of its Five Wise Generals, specializing in intelligence and security. His naval background grants super-sensitive hearing for precise sound-based target location. As an archer, he demonstrates exceptional skill in non-lethal combat, expertly cornering opponents. Ukyo possesses high analytical intelligence, detecting inconsistencies like fabricated voices or anachronistic statue placements, and is bilingual in Japanese and English. His capabilities are rated high in technique (5/5) and reach (5/5), moderate in speed (3/5), and lower in physical power (2/5). Ukyo's pacifism remains central throughout later missions. He objected to lethal weapons during the Treasure Island Arc but accepted Senku's non-lethal petrification strategy. He identified the Why-man's synthetic voice in the New America City Arc. Petrified again during a confrontation with Stanley Snyder in the South America Arc, he was later revived. After three years petrified, he participated in founding Superalloy City and joined the team traveling to San Francisco. Physically, Ukyo is a slim young man of average height (173 cm) with short white hair, green eyes, and boyish features. He typically wears an orange turtleneck, khaki trousers, pointed loafers, and a signature paper cap (later replaced by a Kingdom of Science insignia hat), carrying a bow and quiver with a fur-adorned sling. Personality-wise, he balances idealism with pragmatism, striving to avoid casualties while acknowledging violence may sometimes be necessary. His loyalty intensifies when protecting trusted allies, overriding his usual caution. He initially concealed his compassionate nature to survive in Tsukasa's empire, gradually revealing it after joining the Kingdom of Science.