Yo Uei, a former pre-petrification police officer, built a reputation for reckless conduct and excessive force, often shooting suspects during arrests, hindering his career. Petrified mid-urination against a wall, he was revived by Tsukasa Shishio and served the Tsukasa Empire as an enforcer. Assigned to guard Chrome during the Stone Wars, Chrome escaped under his watch. To evade punishment, Uei faked his death and fled the Empire, directing his subordinates to blame him entirely. He possesses a lean, muscular frame, standing 177 cm tall, with spiky auburn hair. A persistent stone fragment habitually covers his right eye despite repeated removals. His typical outfit is a grey sleeveless yukata, spiked necklace, and ankle bracelets, though he later switches to modern clothing with Kingdom of Science insignia. Initially abrasive and arrogant, Uei dismissed post-petrification humans and frequently belittled others, believing modern humans superior. He demonstrated cowardice by fleeing the Empire and later feigned amnesia to join the Kingdom of Science for safety. Work-averse, he complains about tasks like statue restoration and farming, though profit or power offers motivate him. Despite these traits, he displays occasional loyalty, shielding his subordinates and committing to redeem himself by aiding Yuzuriha in rebuilding petrified statues. Over time, he develops genuine loyalty to the Kingdom of Science, expressing awe at Senku's inventions and wishing he'd met Senku before petrification. His police training grants expertise in tonfa combat and martial arts, plus moderate marksmanship skills that improve with practice. He exhibits above-average running speed and endurance. Statistical ratings are Power: 3/5, Speed: 4/5, Technique: 5/5, Reach: 1/5. Within the Kingdom of Science, Uei frequently clashes with Magma due to similar aggressive personalities and conflicting views on modern versus primitive capabilities. Senku and Gen easily manipulate him into tasks like farming or wielding firearms. During the Treasure Island arc, his firearms experience earns him a gun. After initial poor accuracy, he practices diligently, later contributing to key battles and disarming Ibara. He is petrified multiple times, including conflicts on Treasure Island and in South America. In the New America City arc, he nervously points a gun at the revived Tsukasa before relaxing as threats are assessed. He joins the voyage to America, gambling and complaining about the lack of alcohol until beer is recreated. He participates in combat missions, fighting alligators and shooting at an assailant's plane, though often ineffectively. Later, he helps establish a police force in Corn City, drawing on pre-petrification experience. During the South America arc, Uei voices skepticism about creating diamonds but becomes enthusiastic upon success. He fights American soldiers and suffers a non-fatal gunshot wound while attempting to activate the petrification device. He is petrified again during the global petrification event. Revived years later, he assists in computer construction, delivers supplies across continents, participates in Indonesian farming, and rejoices at dam construction in Japan. His final known appearance sees him petrified alongside Gen during the Moon Mission arc.