Yo Uei (上井 陽 Uei Yō) is a pre-petrification human and former policeman. Originally a member of the Tsukasa Empire, he faked his death after Chrome's escape to avoid the blame, then eventually joins the Kingdom of Science after the stone wars are over.
As penance, he worked with Yuzuriha to rebuild the statues that were destroyed by Tsukasa. Yo also worked in the farming division under Taiju. However, he is constantly butting heads with Magma due to each other's naïvety in their respective worlds.
- 1 Appearance
- 2 Personality
- 3 Abilities and Skills
- 4 History
- 5 Synopsis
- 6 Chapter Appearances
- 7 Trivia
- 8 References
- 9 Site Navigation
Yo is a lean but muscular young man of slightly above-average height with incredibly spiky auburn hair, left to flow wildly behind his head. He has a massive piece of stone covering his right eye. For some inexplicable reason, despite ditching the stone eyepatch several times, it somehow always makes a reappearance.
He typically wears a short, grey sleeveless yukata that leave most of his legs exposed. He has a very large shoulder pad on his left shoulder and wears a spiked necklace. Like many in Tsukasa's Empire, he goes barefoot, though he does decorate himself with ankle bracelets. When Yuzuriha builds a fashion store, Yo wears a modern outfit.
Prior to the petrification, Yo wore a police officer uniform.
He is first shown as being abrasive, rude, and arrogant, having shown off his skills in front of his subordinates to prove how strong he is. He believes himself to be on the same level as Tsukasa, Hyoga and Ukyo when he is little more than a strong-but-unintelligent, violent thug. He also has a tendency to look down on people, especially the Post-Petrification people. He laughs off Chrome's attempt at escape, believing that he was trying to rub two sticks together to create fire to burn his way out (in reality, Chrome was using a battery, but uses Yo's misconception and belittlement to his advantage by feigning ignorance). In addition, he frequently laughs at the "savages" for not understanding modern science, such as laughing at Magma for looking down on modern science (Magma is the person he fights with the most). He can be rather dismissive, believing Senku to have gone nuts in chapter 96 when he starts building his GPS as he can't understand the science behind it. Despite this, he considers modern humans superior to "savages" and takes every chance he can get in proving this.
He is a coward and, once Chrome managed to escape, is quick to leave the Tsukasa's army for fear of punishment. He goes so far as to feign amnesia to join Senku's Kingdom of Science since it would mean a greater chance of survival. He tries to butter up to them by claiming he would like to "redeem himself" by working for Yuzuriha in repairing the broken statues, though this works against him as it proves to be more work than he wished. He is shown to dislike work, often complaining about having to help Yuzuriha's statue fixing (a rather arduous task) and needlework. He similarly complains about farming, though he can be motivated when the promise of profit or power comes along.
Even in his past, he was shown to often disregard rules, once shooting a suspect while claiming that it was because they were trying to flee, and similarly peeing on a wall while being petrified. He has also admitted to being trigger-happy, shooting people on sight. His abrasive, power-seeking personality also makes him easy to manipulate into doing Senku's and Gen's bidding. He often tries to butter up to his superiors while coveting power, though is mostly harmless due to his lack of intellect. He and Magma get into fights often about the capabilities of the "savages" and the capabilities of "modern people", along with their similar personalities, strength, and desire for power and leadership.
Despite this, he does have at least one or two redeeming qualities. While fleeing, he tells his remaining subordinates to tell Tsukasa that he died and to put all the blame of Chrome's escape on him (though this would have no consequences on Yo himself since he would be thought dead, but also no benefit) implying that he at least somewhat cares about his subordinates. He is even willing to redeem himself by helping Yuzuriha out by rebuilding statues with her.
Abilities and Skills
Yo is former cop with a penchant for violence. As such, he's had his fair share of combat experience prior to the Petrification event.
- Police Training: As a former cop, he has training in police combat and is shown to be a somewhat competent combatant with a tonfa.
- Running: After Chrome escaped the jail, Yo assesses the damage to the jail bars before running after Chrome and dodging the pitfall traps. Despite the delay, he still succeeds in catching up to him.
- Marksmanship: Thanks to his experience as a police officer, Yo was trained in the usage of firearms, though due to a lack of practice since he was petrified, he is initially a poor shot, though he is able to improve after some target practice. However, his accuracy and skill is still far below Ukyo.
- Martial Arts: Yo specialises in Tonfa usage in martial arts, and has won the baton category at the Police Martial Arts competition. Yo is very proficient in using the Tonfa, being able to take out a large muscular man in the Tsukasa Empire in one blow.
- Tonfa: When we are first introduced to Yo, he is seen using his second favourite weapon, the tonfa, which he uses very proficiently.
- Gun: When the Kingdom of Science creates a gun during the Treasure Island Arc, they entrust Yo with it, as he's the only member of the KOS that has had any practice in firearms. Although not using it well at first, he eventually begins to use it well once more.
Yo was a seemingly well-known police officer in Japan, being described as 'crazy strong police officer' by some. At some point in his career, Yo won the baton category in the Police Martial Arts Competition. This win would go on to prompt Minami to interview him.
Throughout his career its assumed Yo has arrested and punished many criminals. One instance we see of this is when Yo busts and embezzlement trade for tax fraud. When Yo busts into the room, he addresses the criminals as 'baddies', quite the childish term for a serious job. Yo would make many childish catch phrases throughout his career as a police, another example being 'Boom!'.
When he busts into the room, other men in black suits run in after Yo, to which Yo begins to take them all down with one hit. The two criminals run, and one aims an gun towards Yo and fires. The bullet barely grazes Yo's cheek. In a fit of rage, Yo shoots the criminal, killing him. When questioned about what happened by his superiors, he proudly proclaims he shot the criminal, once again addressing him as 'bad guy' very childishly. He expresses his distaste for trials and how they are a waste of time, and proclaims that if a someone is a criminal or 'bad guy' in his words they should just kill him. This comment infuriates his higher ups, who fire him on the spot. Yo states that he had no future left in that world after this happened.
It is unknown where Yo was at the time of the petrifaction, however it can presumed he was on the streets as he lost his job. Yo claims he was peeing at the time we was petrified.
He is guarding Chrome's cell and talks about his desire to move up the ranks. He, along with his followers, mocks Chrome for his seemingly primitive thinking.
However, Yo attempts to capture Chrome after he escapes, but Chrome spits fake blood on him and hits him in his groin.
Fearing the consequences for his failure, he gives his underlings a false report on his death and to report to everyone that he died. In actuality, he goes into hiding, though he seeks to redeem himself by capturing Chrome again. Finding Ishigami Village, he is about to put his plan into action, but comes across a captured Homura. After she notices him, she asks to be liberated and promises him benefits if he does.
Yo later returns to the Tsukasa Empire, only to join the Kingdom of Science after learning that they won and is impressed by their skill. He lies that he lost his memory and aids Yuzuriha in fixing the petrified humans.
He creates a boat for a contest and ends up making a poorly-constructed raft.
When Senku announces plans to create a hot air balloon, Magma makes fun of him before looking at Yo to see if he is laughing, but the latter is just as confused. Yo is forced to take part in gathering supplies with Yuzuriha and Taiju. He and Magma then get into repeated arguments again.
Yo and Magma get into an argument over whether modern and primitive can do a better job at sewing before he is amazed by the fact that they made a large balloon with the fabric. He soon picks a card from Gen's hand and doesn't get the right one. Yo is subsequently surprised when Chrome appears after running all the way from the village. Yo is then shocked Chrome ran from the village to the Roppongi Hills Mori Tower, surprised with his eagerness. 
He takes up farming, but fails to make a good crop.
Yo is petrified by Ibara and his forces.
His statue and subsequently dumped into the water by the enemy soldiers but it’s collected by Taiju.
After Senku creates a gun, the group realizes that they need an expert with firearms so they He is later depetrified Yo for him to wield against Mozu. Yo is flattered at the thought of being the new Sheriff for the stone world and is even more encouraged when Amaryllis flirts with him to make sure he stays in line. Yo demonstrates his skill by accidentally shooting a snake when he meant to hit another target. He internally resolves to keep to this himself after he is praised by the others.
During the battle, Yo tries to shoot Mozu when he invades the ship, but misses and gets beaten by him. Once Ibara's evil scheme gets exposed to the Petrification villagers, Yo has one bullet to stop him from using petrification weapon again like he did to Kirisame by shooting at the evil minister’s left hand. This time, he gets the shot and acquires the weapon, to his delight.
Unfortunately, he doesn't know how to use it and Ibara uses it to repetrify him.
After the battle, his statue is found underwater by Taiju. Yo is later depetrified by Senku and rejoices in the victory with his allies.
After the potential threat of possible villains rise, Yo agrees before Tsukasa states he can handle it. Yo is scared after he recalls Tsukasa's skill.
He is excited at the prospect of betting on Senku and Ryusui's poker game. 
He bets on Ryusui during the poker game. After Senku wins, Yo is disappointed, especially when his wages go to Ginro.
He later complains on the lack of booze and is excited when beer is recreated. While drunk, Yo rants about his shooting of Ibara while Nikki remarks on how he loves to tell stories.
Yo is later excited by the sight of sea creatures that pass by before they spot land.
Once on land, Yo, along with Ginro and Magma, rejoices at finally being off the ship. The crew of the Perseus separates with Yo among the warrior team who follow the exploration team in the case of an attack. While passing through the river, the Mobile lab is attacked by alligators. However, Yo and the warrior team attack after being driven by their hunger. They defeat most of the beasts while the rest flee in fear. Afterwards, François makes burgers out of the dead alligators to feed the crew, with Yo happy at the meal.
When the group sets up camp, they are alerted by Tsukasa to retreat because of danger. Surely enough, bullets rain down and Yo flees the area with his friends. 
The group then flees the scene while being pursued by the attacker, who is revealed to have built an aircraft, something that leaves Yo in complete shock. Yo desperately shoots at the plane while Hyoga tells him that it's pointless and a waste of ammo, but Yo wants to do at least something. Yo then watches Senku have Kirisame bring down the ship before they procure the downed plane.
Yo is later shocked to see a plane flying over the Perseus and that the enemy has a second one.
When Magma voices a plan to take the fight to Dr. Xeno, Yo protests this absurd plan, but he is smooth talked into going through with it. However, Nikki scolds them and prevents them from through with it. 
He is later seen are ogling Luna while she is making her way around the ship.
When Senku is shot by the enemy sniper, Yo is worried about him. He acknowledged Ryusui being right about using the moment to surprise the enemy while they think they are vulnerable. He is relieved Senku survived and remarks on Francois translating for him.
When Stanley's plane is spotted, Yo alerts the crew are alerted of Stanley's arrival, with them preparing for the Science War.
When Minami notices Ryusui wielding a machine gun, Ryusui tells he that the latter snatched his gun earlier. 
As the battle between Stanley, Senku, and Ryusui took place. When the Perseus came under attack, Yo and his group were confronted by Stanley's unit. A large female soldier charged at them and was able to subdue Magma and Yo. Yo was seen beaten and tied up by her.
Yo later over here is the negotiations between Dr. Brody and Senku who gives the ingredients for the Revival Fluid so that way they can create Corn City.
Yo and the others are tasked with creating diamonds. Yo in particular is amazed by the fact that one can actually create a diamond wishing that he had met Senku thousands of years ago to create such items.
- Both parts of Yo Uei's names are used as interjections. "Yo" for when trying to get someones attention, and "Uei" when surprised, though neither are limited to these situations. The character Yo uses both frequently.
- In the anime, Yo was apparently revived thanks to Minami recognizing him as a "crazy-strong" police officer who won the baton category at a police competition. He was also given a small crush on her.
- He is the first person to be petrified three times.
- The Martial Arts that Yo uses is known as Okinawan Martial Arts.
|Male||Tsukasa Shishio • Hyoga • Ukyo Saionji • Yo Uei|
|Female||Homura Momiji • Minami Hokutozai • Nikki Hanada|
|Male||Dr. Brody • Byakuya Ishigami • Carlos Barrios • Gen Asagiri • Hyoga • Joel • Leonard • Max Adams • Ryusui Nanami • Senku Ishigami • Shamil Volkov • Stanley Snyder • Taiju Oki • Tetsuya Kinomoto • Tsukasa Shishio • Ukyo Saionji • Xeno Houston Wingfield • Yakov Nikitin • Yo Uei|
|Female||Charlotte • Chelsea • Connie Lee • Darya Nikitina • Homura Momiji • Lillian Weinberg • Luna Wright • Maya Biggs • Minami Hokutozai • Mirai Shishio • Nikki Hanada • Yuzuriha Ogawa|