He is a junior lightweight veteran professional boxer. Along with Makunouchi Ippo, Takamura Mamoru, Aoki Masaru and Itagaki Manabu, round up the core members of the Kamogawa Boxing Gym and the series.
His surname is Kimura. In Japan, surnames are listed before given names.
Kimura became a delinquent because he was bullied by an older boy, and when his father went to confront the boy's father, he was pressured and ended up apologising, this made Kimura lose all respect for his father, becoming more violent in both his house and outside, and decided to quit high school without his parents knowing.
Kimura and Aoki Masaru were best friends since kindergarten. In high school they began brawling and causing trouble with students from rival schools, namely North High, which eventually led to their expulsion. Kimura was the most affected by this because he was worried he had disappointed his mother. One day the pair attacked North High's Takamura Mamoru and lost miserably. Seeing Takamura's strength as a boxer, they decided to join the Kamogawa Boxing Gym to try and become strong too.
Despite losing to him in every spar, they continued boxing until they had earned their pro licenses and stepped into the ring. Eventually they forgot about their grudge and became passionate about boxing itself, even looking up to Takamura.
In the anime, Kimura and Aoki watch Makunouchi Ippo and Miyata Ichirou sparring. After the end of the spar, he introduces himself to Ippo. On Ippo's first day at the gym, Kimura and Aoki attempts to train him, however they are stopped by the coach. Ippo, not knowing what Shadow Boxing is, asks Kimura, he then demonstrates shadow boxing. Kimura is seen watching Ippo's and Miyata's second sparring match.
When Yagi announces Ippo's pro debut match opponent is Oda Yūsuke, Kimura remembers him, as Oda started around the same time as him. Kimura, along with the others watch Ippo's fight with Oda, then celebrated after Ippo's first win.
Ippo celebrates his first year at the gym with Kimura, Takamura, and Aoki at the Chuuka Soba. A bit later after Ippo's fight with Jason Ozuma, Kimura sparred with Ippo, noticing the latter is getting stronger. Kimura along with the others, watched Kobashi Kenta's and Hayami Ryūichi's matches on tape. Kimura, along with Aoki, Ippo, and Takamura goes to the training camp at the beach. There, Kimura trained himself and helped Ippo with his training by sparring and throwing tennis balls for Ippo to catch. At the day of the match, Kimura watches Ippo's match against Kobashi.
Kimura attends Takamura's match against JBC middleweight champion, Yajima Yoshiaki. When Takamura went down, Kimura and the others cheers helped Takamura stand up. When Takamura wins the match, earning the JBC middleweight champion belt, Kimura and the others celebrate at the Sugar Ray.
Kimura attends Hayami's match against Yasukawa Kazu, and Aoki's match. Kimura watches Ippo's match against Hayami.
Kimura's main fight in the series is against Mashiba Ryō for the JBC Junior Lightweight championship. Kimura lost despite inventing a new signature move and putting in his best efforts. He also fought twice against Eleki Battery, a national champion. Both fights ended as draws.
Kimura's main role in the story is that of a supporting character, but upon his and Aoki's second entry into the Class A Tournament, they became directly antagonized by Iga Shinobu and his trainer, Baron Kurita. They are now both aiming to settle their grudge with the duo.
Ippo announces his retirement and says his farewells to Kimura, Aoki, Itagaki, and Takamura. Kimura tells Itagaki that he thought he was the first one going to retire, and doesn't know why Ippo retired. One day, Kimura, who is struggling with weight management, is running with the group, Ippo shows up and starts training Kimura as his second. Kimura's match begins, during his match, he has many instances where his seconds had mistakes, and it was a mud match with his opponent until round seven, where Ippo gives Kimura advice about his opponent's left hook. An exhausted Kimura sees an opening for a counter, the counter hits his opponent in the face and falls down, resulting in Kimura winning the match. After boasting about his counter, Kimura asks Ippo if he is okay with being a second, in which he states that he is. After Aoki and Itagaki's match, Kimura explains that Ippo shouldn't nag Itagaki after he wins. When Ippo brings Teru to the gym, Kimura believed you can't judge him by his appearance as Ippo was the same. After seeing Teru's weak punch, he and Aoki teases Ippo for bringing him to the gym.
|WIN||16-6-5||Unknown||KO||7(8), ?:??||1999-06||Tokyo, Japan||N/A|
|DRAW||15-6-5||Unknown||Decision||8(8), 3:00||1998-11||Tokyo, Japan||N/A|
|DRAW||15-6-4||Unknown||Decision||8(8), 3:00||1998-09-15||Tokyo, Japan||Comeback Match|
|LOSS||15-6-3||Unknown||Decision||10(10), 3:00||1997-09-12||Tokyo, Japan||Class-A Tournament Final|
|WIN||15-5-3||Ryuuzaki Takeshi||Decision||10(10), 3:00||1997-02||Tokyo, Japan||
Class-A Tournament First Round
|LOSS||14-5-3||Sim Rex||Decision||5(10)||1997-04-15||Yokohama, Japan||Stopped by doctor due to heavy bleeding on both sides.|
|WIN||14-4-3||Michael Gehon||KO||5(10)||1996-09-12||Tokyo, Japan||
"Operation - World Domination" Semi-Final Match
|DRAW||13-4-3||Eleki Battery||Decision||10(10), 3:00||1996-03||Tokyo, Japan||N/A|
|DRAW||13-4-2||Eleki Battery||Decision||10(10), 3:00||1995-08||
|WIN||13-4-1||Alman Alegria||Decision||10(10), 3:00||1994-10-14||Tokyo, Japan||"Apocalypse Now"|
|LOSS||12-4-1||Mashiba Ryou||TKO||9(10), 2:30||1994-02-17||Tokyo, Japan||"Execution"|
Junior Lightweight Title Match
|WIN||12-3-1||Nefuma Ozca||TKO||5(10), 1:25||1994||Tokyo, Japan||N/A|
|WIN||11-3-1||Pone Morocotte||KO||10(10)||1993-07-11||Tokyo, Japan||N/A|
|WIN||10-3-1||Yokita Fujisawa||KO||6(8), 1:18||1993||Tokyo, Japan||N/A|
|LOSS||9-2-1||Ryuuzaki Takeshi||KO||1(1), 2:06||1992-07||Tokyo, Japan||
Class-A Tournament (Extra Round)
|DRAW||9-1-1||Ryuuzaki Takeshi||Decision||8(8), 3:00.||1992-07||Tokyo, Japan||Class-A Tournament Second Round|
|WIN||9-1-0||Nishimura Hiroshi||Decision||8(8), 3:00||1992||Tokyo, Japan||Class-A Tournament|
|WIN||8-1-0||Kanzaki Shinji||Decision||8(8), 3:00||1992-04-20||Tokyo, Japan||N/A|
|LOSS||?-1-0||Unknown||N/A||N/A||N/A||Tokyo, Japan||Rookie King Tournament, First Round|
|WIN||1-0-0||Hotta Junichi||KO||2(4)||19??||Tokyo, Japan||Pro Debut|
Kimura has a pale skin complexion, black hair color with a flat top hairstyle, and a medium-sized nose. His eye color is black and he has long, thin eyebrows. It is noted by Itagaki that Kimura is moderately handsome.
His training outfit is either a green jumpsuit or a blue t-shirt with pants
During his delinquent days, he had a pompadour hairstyle and wore gold shades with green lens.
Kimura is a smart boxer with a good eye. He lives with his parents and helps them run their flower shop, but makes most of his living from his fights. He has been known to come up with his own original training methods, such as shadow boxing to music. He also tends to speak more politely and can often narrowly avoid Takamura's pranks through guile, and shifting the brunt of the blame on to Aoki.
He and Aoki are best friends and are sometimes referred to as Aokimura (青木村). He tends to be less hard on Ippo than the others and more willing to assist in his training, although he does still tease him occasionally. While Takamura and Aoki often show concern for Ippo, Kimura is the closest of the three of them to being an ideal senpai. He is not above being petty or jealous and gloating. An example would be when he refused to stop celebrating Mashiba's suspension and Sawamura's retirement (as it meant he had less obstacles for the belt), despite Ippo's protests.
Kimura's pathetic love life and constant lack of a girlfriend is a recurring joke in the series, and he even named his pet fish Reiko after a girl who broke his heart.
Like Aoki, he is also highly skilled at baseball, particularly as batter, but as the two of them became delinquents, they lost interest in the sport and abandoned it.
Kimura, like Aoki, possesses a boxing ability that is largely downplayed for much of the series (albeit not quite as badly), with his overall style being defined as a solid, all-around style with a firm grasp on the basics. Miyata stated that as a boxer, Kimura had no weaknesses (despite also not having any outstanding strengths) and Miyata's father said that although he was only ranked third before his fight with Mashiba, his talent surpassed that ranking.
Although renowned for having typically lukewarm boxing abilities compared to other characters in the series, Kimura has occasionally showcased bouts of talent, courage and willpower far beyond he is usually known for in his fights, specifically in his match against Mashiba; the latter himself later admitted that Kimura was his strongest challenger.
As a fast outboxer, Kimura is often asked to be a sparring partner for Ippo and one time for Miyata, though Kimura benefited more from Miyata's sparring.
In the lead-up to Kimura's fight against Mashiba, Miyata identifies Kimura's biggest flaw: as a well-rounded fighter he has no specific weaknesses, but he also has no strengths. Kimura comes to the same realisation when he manages to slip pass Miyata's jabs, but realises he has no plan of attack with the distance closed. Notably, his lack of a Sunday punch makes it difficult for him to intimidate his opponents.
While Kimura does come up with the Dragon Fish Blow, he still does not have an emphasis on particular strengths, unlike Ippo's in-fighting or Miyata's counters.
- Kimura, along with Aoki, appeared earlier in the anime than in the manga.