Yuuma has white spiky hair that curls back. He wears a black shirt and pants for school days. He is fairly thin and has a decent build for sumo.
Initially, Yuuma is arrogant and tough, as he is known as the strongest in Daichi High. He takes several opportunities to bully Ozeki and steals the dojo from him, turning it into a hangout for his delinquent gang, and even destroying Ozeki's dohyo to mock sumo.
After his defeat against Ushio, Yuuma joins the sumo club and as a result becomes more dedicated and is able to get along with his team mates. His main goal in joining is to one day defeat Ushio. Later, it is shown that Yuuma feels extremely guilty about what he did to Ozeki, even after apologizing, and this greatly affects his motivation and performance. Yuuma is also shown to be smart, ranking 18th out of around 320 students, which conflicts with his supposed delinquent personality. He was shown to be taking calculus.
In a lighter, slightly annoying side of him, he's extremely protective of his sister ever since his high school days. Even as adults, he treats Reina as if she were a little girl, even willing to beat up Hinomaru for making her cry and misunderstanding the situation in favor of his sister.
According to Atsugi Jiro, the buffet barbecue shop owner, he also praised his cooking skills on the barbeque, and his immaculate organization on the table.
Yuuma prefers to fight from long range, and uses a sumo revolving around rapid thrusts meant to push the opponent out of the ring. These thrusts resemble karate strikes quite closely. He has good thrusts and a kaishuu (open hand) thrust was enough to stun Sosuske for a brief moment.
Initially, Yuuma gained power for strikes from the upper body, meaning that if one stepped back, Yuuma would put his legs together and fall. However, after refining his karate, Yuuma gains much more powerful and precise strikes that come from the lower body. However, he still cannot fight at close range, and if the opponent grabs his loincloth, he is almost helpless.
He also got his finisher, Castle Break Punch using a leg trip as an anchor and feint set-up. His refined karate also helped him anticipate opponent's movements because he cannot see their whole bodies when fighting in close range.
He even sold the entire weakness by inviting the grab, then counter into Deformed Three-point Attack, which is a belly-to back throw from an inside leg trip, with a grab to the back of the opponent's neck.
District Preliminary arc
At the start of the story, Yuuma had already taken over the dojo and is known as the strongest of Daichi High. When Ushio shows defiance against him, he ruins Ozeki's dohyo out of spite for the sumo club. Yuuma then promises to give the key to the dojo if Ushio could survive being beaten for 10 minutes. Despite going for 15 minutes, Ushio was still standing and had barely taken damage. He then knocks out Yuuma with a buchikamashi. Yuuma calls off his henchmen and admits his defeat. He is then dragged along by Ushio to Ishigami High, in an attempt by Ushio to make Yuuma join the club. Yuuma goes to about 260 shiko before being unable to keep up with the training and observes Ushio defeating Kanamori. He then tries to settle things with Ushio, but is completely defeated again and called a coward. Yuuma takes this as a challenge to defeat Ushio and joins the sumo club once Ozeki forgives him for past actions
In the district preliminary tournament, Yuuma loses his first 2 matches against people from Kawato and Nishigami High, since he went for the loincloth. In Daichi's third match, Ushio tells Yuuma to find his own style, and Yuuma uses a style revolving around rapid thrusts and dodging his opponent's thrusts to secure a win. Thanks to the improved Yuuma and Ozeki, Daichi High continues to win and soon they face off against Ishigami High in the finals. Despite Yuuma's efforts, he loses to Kanamori in a thrusting battle. Ultimately, Daichi High is eliminated, as only Ushio won against Ishigami. Yuuma and Ozeki regret not being able to help Ushio and promise that they will become the best team in Japan.
Sumo Recruitment arc
The sumo club sets up a stall with chanko in order to recruit members. Yuuma makes good chanko to replace the terrible one made by Ushio. However, the people came for chanko and no one was interested in sumo. Luckily, Ushio recruits Chihiro in a spar, and Mitsuhashi joins after watching that spar. When Reina is frustrated that the sumo club has enough members, Yuuma explains the thrill of sumo to her and declares that he will defeat Ushio so that Reina could be proud of him.
Yuuma is now able to keep up with the training and completes 300 shiko stomps. He spars with Chihiro, but loses as he is unable to cope with Chihiro's charging head on style. The sumo club sets their sights on the Kanto newcomers tournament.
Kanto Newcomer Tournament arc
Yuuma is determined to place higher than the new members as a senpai of the club. He encourages Chihiro and Mitsuhashi by telling them that they will show Daichi High's true worth, in a manner similar to Ushio's speech. Yuuma breezes through the first few rounds, using his style of thrusts to push the opponent back. He makes it all the way to the semi finals. Chihiro tells him that he is the only one who can properly fight against Sosuke due to his ignorance about Yamato Kuni. Yuuma reflects about how his pride was crushed and decides to take back the confidence lost in sumo by winning in sumo before he faces off against Sosuke. He endures Sosuke's initial charge by using his arms as a cushion, then he strikes back with a karate like thrust called kaishuu (open hand) on the tip of his shoulder. This pushes Sosuke back and breaks his stance. Yuuma continues his assault of strikes and puts Sosuke on the defensive, but is still stuck at the edge of the ring. Sosuke then blocks his strikes and gradually closes in. Yuuma tries sidestepping and going for another kaishuu, but it takes too long to execute. Sosuke grabs his loincloth and wins the match.
Kirihito's Training arc
After Sosuke winning the kanto newcomers tournament, Kirihito joins the sumo club deciding to be their coach. However, Yuuma says that he does not want someone without strength as their coach. Kirihito accepts the challenge and pits middle schoolers against the sumo club. Yuuma is up first, and starts to take the momentum with thrusts. However, at the moment where he puts his legs together and tries a thrust, his opponent steps back, causing Yuuma to fall and lose. Kirihito explains that Yuuma only uses his upper body for his thrusts and as such is unable to keep his balance when someone steps back. The other members, including Ushio, lose in a similar manner. The training starts with fishing on a boat. Yuuma and the others are made to do shiko on the boat every morning in order to increase their balance. Later, Yuuma practices thrusting at ping pong balls while using his legs and keeping his back straight in order to strengthen his lower body. On a day for self training, Yuuma returns to his old karate gym upon Kirihito's suggestion to become a karate master. He tries to convince his former teacher Takani to teach him karate again, but she is adamant and does not believe that Yuuma has changed from being a delinquent. Once Yuuma tells her that he wants to atone for his past actions, she decides to teach him.
Interhigh Preliminary arc
The Daichi sumo club comes in now with most members having a reputation. Yuuma has his own as the striker of Daichi. In the first round of the tournament, Yuuma uses multiple and rapid kaishuus in order to push his opponent out of the ring. He is able to keep his balance a lot better than before and also has more power in his strikes. The club continues to advance in the tournament, with Yuuma continuing to win. The finals results in Daichi vs Ishigami, and Yuuma is put up against Kanamori. Yuuma takes a lion dog stance with his back straight up so that he can bring out his strikes faster. However, Kanamori gains the momentum first by using his own strikes, called the cannon. Yuuma is pushed to the edge of the ring and remembers that karate is about a flexible transition between defense to offense by receiving blows. He uses makibuse, a karate based inashi, where he repels Kanamori's strike and pulls him to the edge of the ring, switching their positions. Yuuma then uses otsuki, a follow up thrust, only for Kanamori to block it with his forehead. He then charges and knocks Yuuma to the edge of the other side. Yuuma remebers that he still has responsibilities to carry out and that he has one more desperate move left. Yuuma uses a foot sweep to hook onto Kanamori's leg, then uses that to accelerate and throws an extremely powerful thrust called battering palm that stuns Kanamori. Yuuma tries to finish it off only for Kanamori to trap his arm and then grab his loincloth, then using harimamanage and winning the match. Although Yuuma wins the battle of thrusts, he cannot win the overall match.
- Gojō Yūma vs Ushio Hinomaru (Knockdown within 15 minutes) Loss
- Gojō Yūma vs Kanamori (District Preliminary) - Loss
- Gojō Yūma vs Kunisaki Chihiro (Sparring Match)
- Gojō Yūma vs Kuze Sōsuke (Kanto Newcomer Tournament) - Loss
- His blood type is A.