In Inazuma Eleven Ares no Tenbin, Kozoumaru is a short, overweight boy with slightly tanned skin and spiky, dark purple hair that is grey around his temples. He has sharp black eyes, thin eyebrows, and a small, pointy nose.
His casual wear consists of a white shirt under a red jacket with white buttons, dark blue shorts, and white shoes.
In Inazuma Eleven Orion no Kokuin, after he wasn't selected as a member of Inazuma Japan, he went to training in the mountain. As a result, he becomes taller and slimmer, looking more like his idol, Gouenji Shuuya. He also has his collar on his kit up as well like Gouenji.
Kozoumaru is mostly serious and doesn't smile too much, but he also has a soft side. In the beginning, he's very arrogant with his new teammates, due to believing a team of kids that don't have any hissatsu can stand no chance against other teams in the Football Frontier, as well as being annoyed by their cowardice, but he starts to care more for them after revealing his backstory in episode 3. He is a big fan of Gouenji because of an advice he gave to him that changed Kozoumaru's life. He has a sort of rivalry with Goujin, often snarking at him when things don't go the way he wants, which annoys Goujin even more.
Inazuma Eleven Ares no Tenbin
Kozoumaru was watching from the school as the other Inakuni soccer club's members practiced outside. Later, while Asuto was trying to convince the other Inakuni members to go to Tokyo and play in the Football Frontier against Seishou Gakuen, he reappeared and interrupted him, stating that the team was acting as if they already lost. He explained that he traveled to Inakunijima for special training and wonders if a bunch of cowards like them could do anything, angering Goujin. He went further, saying that a bunch of chumps already scared before a match would have no chance to win at the Football Frontier. Goujin tried to argument they might be able to win one or two matches if they tried hard enough, but Kozoumaru calmly stated that the Football Frontier is where Japan's best team is decided and, from the get go, the committee will ask weak schools to withdraw before even trying. Moreover, he claimed a team without a single Hissatsu technique like the Inakuni would have no chance at all and that they'd be better finding another hobby besides soccer. He was slightly surprised when Asuto said he was going to do it anyway. During the match against Seishou Gakuen, he scored Raimon's first and only goal with Fire Tornado. He then made a backflip to commemorate it. However, in the end, Seishou Gakuen defeated Inakuni Raimon with a score of 10-1. After the match ended, everybody except him started crying for losing, until Shimabukuro Ikutarou offered to sponsor the team and everybody, including Kozoumaru, became happy.
When Kozoumaru was talking with Asuto during dinner, it was revealed that he used to be a defender who was not very good at his position. However, after Gouenji Shuuya stopped a thug Kozoumaru was chasing by kicking a ball towards him, Gouenji gave the advice that he should be on the opposite side of the field. After this, Kozoumaru became a fan of Gouenji and started to play as a forward.
Inazuma Eleven Orion no Kokuin
Along with the rest of his team, Kozoumaru was present when Inazuma Japan was announced but he wasn't selected as a member. When the Inakuni players of Inazuma Japan visiting their former friends before departing to Russia, Kozoumaru wasn't present. It was stated that he was training on his own.
In episode 34, he suddenly joined Inazuma Japan and surprised the team with his new appearance. He has become taller and slimmer, looking more like Gouenji. He told the team about his vigorous exercises and training in the woods, running with the trees as obstacles, leaping over rivers and even facing a brown bear.
Inazuma Eleven SD
All stats are at S-rank, level 50, limit break 10, fully upgraded, all skills learned and all kizuna unlocked.
- GP: 223
- TP: 101
- Kick: 61
- Dribble: 42
- Block: 34
- Catch: 25
- [SH] Hokkyoku Guma 2gou (Override)
- [SH] Meteor Drop
- [SH] Counter Drive
- [SH] Victory Line
- [SH] Hidaruma Bakunetsudan
- [SH] Last Resort
- His title is おデブなエースストライカー.
- In dub version, he's called the new kid on the block.
- In Inazuma Eleven Ares no Tenbin manga he's the first player to get a yellow card.
- He also got a red card during the match against Perfect Spark after he deliberately injured Lus Kasim, making him the first member of Inazuma Japan in the entire series to get a red card, excluding the incident in Chrono Stone.
- He used to be a defender until the first meeting with Gouenji who recommended him to try changing himself.
- Despite being right-footed, shown by his version of Fire Tornado and Bakunetsu Storm, he was able to perfectly execute Last Resort with his left foot.
- He appeared as an obtainable Yo-kai in the collaboration with Yo-kai Watch Puni Puni, another game made by Level-5.