Ukyo Saionji, a modern-day survivor revived by Tsukasa Shishio, served as a high-ranking lookout and intelligence gatherer within the Tsukasa Empire. His pre-petrification role as a sonar technician for the SDF Navy granted him exceptionally sensitive hearing. This ability enables him to pinpoint targets through sound alone and discern subtle audio cues from great distances. Though maintaining a position among Tsukasa's top commanders post-revival, Ukyo privately opposed the empire's violent methods, especially the destruction of petrified statues which he viewed as murder. He concealed this moral stance while gathering intelligence, awaiting a chance to oppose Tsukasa nonviolently. His defining pacifism drives him to consistently advocate against unnecessary bloodshed and seek non-lethal conflict resolution. This principle prompted his defection to the Kingdom of Science after Senku Ishigami guaranteed no lives would be lost in their campaign against Tsukasa. Once this promise was fulfilled, Ukyo became a loyal Kingdom member and one of its Five Wise Commanders, specializing in security and intelligence. Despite his aversion to violence, he acknowledges its occasional necessity and reluctantly engages in combat when alternatives fail. This complexity manifests during hunts, where he apologizes to animals before killing them, and in battles, where his archery incapacitates rather than kills—cornering foes with warning shots or severing ropes to free allies. Guilt over earlier inaction during Tsukasa's reign fuels his commitment to protecting others, leading him to risk his life to intercept attacks meant for allies like Senku. Physically slim yet toned, Ukyo has short white hair, blue-green eyes, and boyish features. He typically wears a long orange turtleneck, khaki trousers, pointed brown loafers, and a signature paper cap—later replaced by one bearing the Kingdom of Science insignia after his South American revival. Like other petrified humans, he bears a petrification scar, which he later recreates as a symbol of loyalty to Senku. He is rarely without his bow and quiver, tools central to his combat style. Ukyo's abilities make him a formidable asset. His super-sensitive hearing enables advanced reconnaissance and threat detection, while his archery skills—rated 5/5 in technique—allow precise non-lethal strikes like pinning clothing to prevent falls or disarming foes. He tactically combines these traits, using environmental sounds to mask movements or exploiting distractions for positional advantages. His intellect is evident when deducing deceptive strategies (identifying Gen's voice mimicry), analyzing inconsistencies (anomalous statues on Treasure Island), and solving technical problems (recognizing Chrome's drill design). Bilingual in Japanese and English, he uses English for covert communications. These skills contribute to major missions: constructing the Perseus, the Treasure Island expedition, and the global pursuit of the petrification source. His story spans multiple arcs. During the Stone Wars, he secretly aided Senku's allies—smuggling a battery to Chrome and lying to Tsukasa about the phone project—while coordinating to dismantle the empire nonviolently. In the Age of Exploration, he helped revive Ryusui Nanami, contributed to shipbuilding, and joined the voyage to Treasure Island. There, he identified underwater statues' temporal inconsistencies and was petrified during an attack; his arrow disrupted the petrification device, saving Ginro. Post-revival, he participated in defeating Ibara and deduced the "Why-man" entity used synthesized versions of Senku's voice. In the New America City arc, he assisted in confronting Dr. Xeno's group, translated Morse code, and advanced toward South America. During the South America mission, he was petrified again by the worldwide beam. Three years later, Suika located and safeguarded his statue. Upon revival, he helped establish Superalloy City and then led a team to San Francisco as part of the global effort to reach the moon, continuing intelligence and security operations against the Why-man threat.