On August 24, 2002, Fukushima fought Oscar Larios for the Super Bantamweight Interim WBC Title, but he ended up losing in the 8th Round by TKO. In 1969, Kamogawa opened the gym. [2] By twenty years, the gym had produced two Japanese champions and one OPBF champion, Miyata Senior. The gym also had boxing manager, Haruhiko Yagi, trainer Shinoda, boxers Mamoru Takamura, Ichirō Miyata, Baron Kurita, Masaru Aoki, and Tatsuya Kimura, however, Baron soon quit due to Takamura. Takamura invited Ippo Makunouchi to the gym, and, after sparring with Miyata, he became a member of the gym. After a second spar between Ippo and Miyata, Miyata and his father left the gym so that Miyata could face Ippo in the professional ring. Years later, the gym got a JBC middleweight belt won by Takamura, and Naomichi Yamada became a member of the gym for a short time before leaving due to having to move out of town. A JBC featherweight belt was later won by Ippo. Manabu Itagaki joined the gym, and Takamura later won the WBC junior middleweight belt until he relinquished it to move a weight class up. JB Sports Gym appeared in Episode 4 of Fake Affair (偽装不倫) or Gisou Furin, a Japanese Drama based on the manga with the same name. A character in the series is a boxer, and he is seen at JB Sport Gym training in the episode. However, the gym name was changed to Toyokuni Boxing Gym (豊国ボクシングジム). After Ippo retired when he lost to Antonio Guevara, he became a trainer for the boxers, and Taihei Aoki and Kintarō Kaneda soon joined because of him. When Takamura defeated world champion Keith Dragon, the gym acquired the WBC super middleweight belt. The Kawahara Boxing Gym member Nakatsuka is based on Takahiro Nakatsuka, with the same surname and similar appearance. The "Monkey" shirt Nakatsuka wears is a reference to the real life Nakatsuka's association with monkeys and boxing, calling himself the "Monkey Boxer." [33]

On October 26, 2019, Kyosuke Sawada managed to defeat Kazuki Tanaka in the Strongest Challenger Tournament (Class A Tournament) [30], which secured him a spot in the Champion Carnival in 2020 with a Japanese Bantamweight title fight against the current champion Yusuke Suzuki. Yusuke Suzuki was previously one of two boxers that had defeated Sawada early in his career. On April 24, 2019 [35], Morikawa announced at JB Sports that he was sponsoring a Class A Tournament with Dangan Promotion for Featherweights as part of his 30th year anniversary. The winner of the tournament will win 1 million yen prize, and an appearance in the Hajime no Ippo story. For details, see Featherweight Tournament. To help honour Hajime no Ippo's 30 year mark, Joshin stores collaborated with Morikawa from 2/8/2019 to 3/3/2019 in a promotion. In the weekly flyer ad for Joshin, it showcased JB Sports Gym with having various boxers appear in it.On November 30, 2019, Tamura Ryoichi won the Super Bantamweight OPBF Silver title by defeating Moensaku Yor at Sunworld Dynasty Hotel in Taipei, Taiwan. Morikawa been known to base some character's names off of some boxers from JB Sports. Itagaki Manabu is based on Fukushima Manabu. In File 148 of Mou, Shimasen Kara manga, JB Sports Gym appears in it. Mou Shimasen Kara is a manga done by a former assistant of Morikawa, Nishimoto Hideo. Founded by Genji Kamogawa years after his retirement, the gym has two stories with a basement. The gym's structure is cubical, while in the anime it is more rectangular. On the first floor, there are a set of six windows connecting to each other, two sets of four windows in the anime. There are two horizontal sliding windows at the second floor, while there is four in the anime. The Charisma Brothers and Fischer's -フィッシャーズ- Youtubers made a short real life Hajime no Ippo film in 2016, where they filmed live-action scene taken from a character's point of view. Part of it was film at JB Sport.

The gym then received the WBC middleweight belt by Takamura after he defeated David Eagle. Ippo had his JBC featherweight belt relinquished to move to the world stage. Takamura defeated world champion Richard Bison, making the gym acquire the WBA middleweight title. JB Sports Gym appeared in Chapter 103 and Chapter 104 of GTO Paradise Lost, where a sparring match is taken placed. Takahashi Naoto, former pro-boxer, who Miyata Ichirō is based on and friends with Morikawa, was the first coach for JB Sports, but later leaving the position in 2007. On June 4, 2005, he was scheduled to fight against Vladimir Sidrenko for the WBA Bantamweight title, but the match was postponed due to Sidrenko having a right thumb fracture.The match was rescheduled for October 15, 2005, but the match was canceled instead due to Fukushima rupturing his right calf muscle. The entire match was stream for free online, where you can see Morikawa act as a 2nd during his boxers matches. Morikawa's gym was originally called JB Sports Club (JBスポーツクラブ), but changed the name over to JB Sports Boxing Gym. The gym also sells some Hajime no Ippo related merchandise like T-shirts, key chains, towels, and other sorted objects.

The first floor and basement serve as training areas while the second floor contains Kamogawa's office. Both the first floor and basement also contain boxing rings in them. After Takamura defeated Bryan Hawk, he put a bronze statue of himself on the roof of the gym. Itagaki mentions that the reason why Kamogawa Boxing Gym doesn't get a lot of new members is because of the "hellish training" that Takamura, Aoki, and Kimura put them through. Even Ippo unintentionally scares away new members when they see him working out. [20] In Chapter 1218, Hanamori Seigo and Shintomi Ryō names appeared in the series listed from BJ Gym. Both are boxers from the JB Sports Gym. On January 12, 2019, Tamura Ryoichi became the JBC Super Bantamweight Champion. He fought for the vacant title against Mugicha Nakagawa (武田勇太).

On February 14, 2000, Fukushima Manabu became the Super Bantamweight JBC Champion after defeating Yutaka Manabe. He lost the belt in his 2nd title defense to Setsuo Segawa on July 15, 2000. For their debut match, George Morikawa would act as their 2nd (which he only does part of the time.) Dangan Boxing Promotions and Rizin (MMA) is set to use Hajime no Ippo themed tape during official matches in 2019.