| Personal information | |
|---|---|
Nickname | Chukyo no Kaibutsu (中京の怪物) "Monster of Chukyo"
|
| Born | (1995-06-15)15 June 1995 (age 30) Tajimi, Japan |
| Height | 5 ft4+1⁄2 in (164 cm) |
| Weight | |
| Boxing career | |
| Reach | 64+1⁄2 in (164 cm) |
| Stance | Orthodox |
| Boxing record | |
| Total fights | 22 |
| Wins | 20 |
| Win by KO | 11 |
| Losses | 2 |
Kosei Tanaka (田中 恒成,Tanaka Kōsei; born 15 June 1995) is a Japanese formerprofessional boxer who competed from 2013 to 2024. He is afour-weight world champion, having held theWorld Boxing Organization (WBO)mini-flyweight title from 2015 to 2016; the WBOjunior-flyweight title from 2016 to 2017; the WBOflyweight title from 2018 to 2020; and the WBOjunior-bantamweight title in 2024. Upon winning his first world title in only his fifth bout, he became the fastest Japanese fighter ever to become a world champion. Along withVasyl Lomachenko, he is also the fastest ever fighter to win titles in three weight-classes, having accomplished the feat in only 12 bouts. He also surpassed Oscar De La Hoya to become the fastest four division champion, setting the bar at 21 fights.[1]
As a child, Tanaka suffered fromLegg–Calvé–Perthe disease. Despite this, he took up boxing and won four national high school tournaments competing as an amateur in thejunior-flyweight division. At the continental and international level he was a quarter-finalist at the 2012Youth World Championships and a silver medalist at the 2013ASBC Asian Confederation Youth Boxing Championships. At Chukyo Highschool he trained under formerOPBF super flyweight champion Hideyasu Ishihara. He finished his amateur career with a record of 46-5 (13 KO/RSC). He was not stopped during his amateur career.[2]
Tanaka turned pro at the age of 18 in 2013. In November 2014, Tanaka defeated previously unbeatenRyuji Hara via tenth-roundtechnical knockout (TKO) to win the OPBFmini-flyweight title. In his next fight, Tanaka decisioned Julian Yedras (117–111, 117–111, 115–113) to win theWBO mini-flyweight title.[3] Tanaka holds the Japanese record for winning a world title in the fewest fights (five), surpassing the previous record held byNaoya Inoue of six fights.[4] Tanaka's only title defense at mini-flyweight came againstVic Saludar, whom he knocked out in round six after a left hook to the body. Saludar knocked down Tanaka in round six, and was ahead on all scorecards prior to the stoppage.[5]
In December 2016, Tanaka challenged former mini-flyweight title holderMoisés Fuentes for theWBO junior-flyweight title. Tanaka dominated Fuentes, dropping him in round five before referee Raul Caiz Jr stopped the fight, giving Tanaka a TKO victory. With the win, Tanaka became a two-weight world champion in just eight fights.[6] Tanaka's first defense came against prospectÁngel Acosta. The former won a wideunanimous decision (UD) (117–110, 117–110, 116–111) and dropped Acosta once. Acosta had won all 16 of his previous fights by knockout.[7]
Tanaka's second defense took place in September 2017 against little-known fighterPalangpol CP Freshmart. Tanaka was a huge favorite going into the fight, but Palangpol would prove to be Tanaka's toughest challenger so far, dropping the defending champion once in the first round and trading back-and-forth combinations for the rest of the bout. After a thrilling fight, Tanaka would finally gain the upper hand in round nine, as he knocked down Palangpol and continued to land big combinations as the challenger struggled to connect. Eventually, the referee stepped in and stopped the fight at 1:52 in round nine.[8][9][10]
Tanaka had previously sought a unification bout againstWBA titleholderRyoichi Taguchi in December,[11] but injuries during the fight against Palangpol would prevent him from fighting on that date.[12]
In December 2017, Tanaka vacated his junior-flyweight title to move to theflyweight division.[13] In September 2018, Tanaka defeatedSho Kimura to capture theWBO flyweight title, equallingVasyl Lomachenko's record of becoming a three-weight world champion in just 12 fights.[citation needed]
In March 2019, Tanaka fought former WBA, IBF, lineal and The Ring junior flyweight champion and domestic rivalRyoichi Taguchi for the first defense of his WBO flyweight title in a one sided bout described as "action packed" by spectators. After the fight, Tanaka expressed regret that he did not deliver a knockout.[14]
In August 2019, Tanaka foughtJonathan González after losing on all three judge's scorecards leading up to the seventh round, Tanaka delivered a brutal knock out to make a second successful defense of his WBO flyweight title.[15]
On New Year's Eve in 2019, Tanaka foughtWulan Tuolehazi, Tanaka delivered a brutal third-round knockout after a one sided fight to defend his WBO flyweight title for the third time. Shortly after the bout, he vacated his WBO flyweight title, announcing that he intended to fightKazuto Ioka for his WBO super flyweight title.[16]
Tanaka faced WBOsuper flyweight championKazuto Ioka on New Year's Eve 2020 in an attempt to win amajor title in four divisions in the fewest fights. He would have become the second Japanese champion to win a major title in four divisions if he was victorious, the first being his opponent, Ioka.[17] After a competitive first four rounds in which Tanaka was the aggressor and Ioka found success with counter punches, Ioka dropped his opponent in the fifth round with a counter left hook. With about a minute left in the sixth round, he again knocked Tanaka down. In the eighth round, Ioka caught his opponent with another hard counter left hook, and referee Michiaki Someya caught Tanaka before he could fall and waved off the fight, with Ioka inflicting Tanaka with his first professional loss and retaining his WBO title via eighth-round technical knockout.[18]
Tanaka was booked to face the one-time WBA super-flyweight title challenger Sho Ishida on 11 December 2021, at the International Conference Hall inNagoya, Japan.[19] He won the fight by split decision, with two judges awarding him a 96-94 and 96-95 scorecard respectively, while the third judge scored the fight 96-94 for Ishida.[20]
Tanaka faced the reigning OPBF and WBO Asia Pacific super flyweight champion Masayoshi Hashizume, for the latter title, at theKorakuen Hall in Tokyo, Japan on 29 June 2022.[21] The fight headlined the "89th Phoenix Battle" and was broadcast by Hikari TV.[22] Tanaka won the fight by a fifth-round technical knockout.[23] Tanaka vacated the WBO Asia Pacific title on 23 August 2022.[24]
Tanaka then faced Yanga Sigqibo on 11 December 2022, at the Takeda Teva Ocean Arena in Nagoya, Japan.[25] He won the bout by unanimous decision.[26]
Tanaka was originally scheduled to make the first defense of his WBO super flyweight title against Jonathan Rodriguez atRyōgoku Kokugikan in Tokyo, Japan on July 20, 2024.[27] However, this fight was called off the day before it was due after Rodriguez missed weight by nearly seven pounds.[28]
Tanaka made his first defense against South African Phumelele Cafu on October 14, 2024. The fight was held atAriake Arena in Tokyo.[29] He lost the bout by split decision.[30]
Tanaka announced his retirement from professional boxing in June 2025 citing repeated eye injuries. According to Tanaka despite multiple surgeries the vision in his right eye is still "severely distorted" and he is unable to focus with both eyes.[31][32] In November 2025, he discussed retirement with Ring Magazine. He continued to stay active, participating in public speaking, organizing boxing events, and providing commentary. He aimed to open a boxing gym in 2026, with a long-term goal of establishing 100 gyms. In the interview, he expressed some disappointment about not achieving the status of a five-weight or unified world champion in his career.[33]
Tanaka balanced professional boxing with school and in 2019 graduated with a degree in economics fromChukyo University.[34] He is the cousin of Japanesefigure skaterYuhana Yokoi and younger brother ofamateur fighterRyomei Tanaka. He said that he admiresNaoya Inoue in an interview withThe Japan Times.[35]
| 22 fights | 20 wins | 2 losses |
|---|---|---|
| By knockout | 11 | 1 |
| By decision | 9 | 1 |
| No. | Result | Record | Opponent | Type | Round, time | Date | Location | Notes |
|---|---|---|---|---|---|---|---|---|
| 22 | Loss | 20–2 | Phumelele Cafu | SD | 12 | 14 Oct 2024 | Ariake Arena, Tokyo, Japan | Lost WBO junior-bantamweight title |
| 21 | Win | 20–1 | Christian Bacasegua | UD | 12 | 24 Feb 2024 | Ryōgoku Kokugikan, Tokyo, Japan | Won vacant WBO junior-bantamweight title |
| 20 | Win | 19–1 | Pablo Carrillo | TKO | 10 (10),2:43 | 21 May 2023 | Paloma Mizuho Arena, Nagoya, Japan | |
| 19 | Win | 18–1 | Yanga Sigqibo | UD | 10 | 11 Dec 2022 | Takeda Teva Ocean Arena, Nagoya, Japan | |
| 18 | Win | 17–1 | Masayoshi Hashizume | TKO | 5 (12),2:52 | 29 Jun 2022 | Korakuen Hall, Tokyo, Japan | WonWBO Asia Pacific junior-bantamweight title |
| 17 | Win | 16–1 | Sho Ishida | SD | 10 | 11 Dec 2021 | International Conference Hall, Nagoya, Japan | |
| 16 | Loss | 15–1 | Kazuto Ioka | TKO | 8 (12),1:35 | 31 Dec 2020 | Ota City General Gymnasium, Tokyo, Japan | ForWBO junior-bantamweight title |
| 15 | Win | 15–0 | Wulan Tuolehazi | KO | 3 (12),2:29 | 31 Dec 2019 | Ota City General Gymnasium, Tokyo, Japan | Retained WBO flyweight title |
| 14 | Win | 14–0 | Jonathan González | TKO | 7 (12),2:49 | 24 Aug 2019 | Takeda Teva Ocean Arena, Nagoya, Japan | Retained WBO flyweight title |
| 13 | Win | 13–0 | Ryoichi Taguchi | UD | 12 | 16 Mar 2019 | Memorial Center, Gifu, Japan | Retained WBO flyweight title |
| 12 | Win | 12–0 | Sho Kimura | MD | 12 | 24 Sep 2018 | Takeda Teva Ocean Arena, Nagoya, Japan | WonWBO flyweight title |
| 12 | Win | 11–0 | Ronnie Baldonado | TKO | 9 (10),2:26 | 31 Mar 2018 | International Conference Hall, Nagoya, Japan | |
| 10 | Win | 10–0 | Palangpol CP Freshmart | TKO | 9 (12),1:29 | 13 Sep 2017 | Edion Arena,Osaka, Japan | Retained WBO junior-flyweight title |
| 9 | Win | 9–0 | Ángel Acosta | UD | 12 | 20 May 2017 | Takeda Teva Ocean Arena, Nagoya, Japan | Retained WBO junior-flyweight title |
| 8 | Win | 8–0 | Moisés Fuentes | TKO | 5 (12),1:52 | 31 Dec 2016 | Memorial Center,Gifu, Japan | Won vacantWBO junior-flyweight title |
| 7 | Win | 7–0 | Rene Patilano | KO | 6 (10),2:23 | 28 May 2016 | International Conference Hall, Nagoya, Japan | |
| 6 | Win | 6–0 | Vic Saludar | KO | 6 (12),2:15 | 31 Dec 2015 | Aichi Prefectural Gymnasium, Nagoya, Japan | Retained WBO mini-flyweight title |
| 5 | Win | 5–0 | Julian Yedras | UD | 12 | 30 May 2015 | Park Arena Komaki,Komaki, Japan | Won vacantWBO mini-flyweight title |
| 4 | Win | 4–0 | Ryuji Hara | TKO | 10 (12),0:50 | 30 Oct 2014 | Korakuen Hall,Tokyo, Japan | WonOPBFmini-flyweight title |
| 3 | Win | 3–0 | Crison Omayao | KO | 1 (10),1:55 | 20 Jul 2014 | International Conference Hall, Nagoya, Japan | |
| 2 | Win | 2–0 | Ronelle Ferreras | UD | 8 | 16 Mar 2014 | International Conference Hall, Nagoya, Japan | |
| 1 | Win | 1–0 | Oscar Raknafa | UD | 6 | 10 Nov 2013 | International Conference Hall,Nagoya, Japan |
| Sporting positions | ||||
|---|---|---|---|---|
| Regional boxing titles | ||||
| Preceded by | OPBFmini-flyweight champion 30 October 2014 – 30 May 2015 Won WBO world title | Vacant Title next held by Xiong Chaozhong | ||
| Preceded by Masayoshi Hashizume | WBO Asia Pacific super-flyweight champion 29 June 2022 – 2022 Vacated | Vacant Title next held by Tsubasa Murachi | ||
| World boxing titles | ||||
| Vacant Title last held by Katsunari Takayama | WBO mini-flyweight champion 30 May 2015 – 7 April 2016 Vacated | Vacant Title next held by Katsunari Takayama | ||
| Vacant Title last held by Donnie Nietes | WBO light-flyweight champion 31 December 2016 – 30 November 2017 Vacated | Vacant Title next held by Ángel Acosta | ||
| Preceded by | WBO flyweight champion 24 September 2018 – 31 January 2020 Vacated | Vacant Title next held by Junto Nakatani | ||
| Vacant Title last held by Junto Nakatani | WBO super-flyweight champion 24 February – 14 October 2024 | Succeeded by | ||
| Records | ||||
| Preceded by Naoya Inoue 6 fights | Fastest Japanese fighter to win a world title 5 fights 30 May 2015 – present | Incumbent | ||
| Preceded by Vasyl Lomachenko tied on 12 fights | Fewest professional fights to win a major world title inthree weight classes 24 September 2018 – present | |||
