Japanese Fighters Database: Records, Titles & Weight Classes
Japan produces an outsized share of the world's elite fighters — from undisputed boxing champions to RIZIN headliners to K-1's most decorated kickboxers. This page tracks every Japanese fighter with a profile on KIAI in one place: weight class, promotion, record, and title history, machine-extracted from our own verified fighter database — no estimates, no scraped numbers.
The numbers, as of August 21, 2026
- 44 fighters tracked across three sports: 28 in MMA, 9 in kickboxing, 7 in boxing
- Combined record: 850 wins, 223 losses, 14 draws
- 34 of 44 (about 77%) hold or have held a professional title — from undisputed world titles (Naoya Inoue in boxing; Kyoji Horiguchi, a former RIZIN bantamweight champion, now in the UFC) down to regional and interim belts
- 43 active, 1 retired (Takeru Segawa, a three-division K-1 kickboxing champion)
- Spread across nine promotions: RIZIN (19 fighters), boxing sanctioning bodies (7), UFC (4), ONE Championship (4), RISE (4), DEEP (2), Shooto (2), and K-1/Krush (2)
How this data is built
Every row below comes from KIAI's own fighter profile pages, not a third-party database. Each profile is built and updated to the same standard described in our editorial policy: record, weight class, and titles are checked against the sanctioning body or promotion's own record-keeping, not carried forward from an old source. This page is a machine-generated rollup of those profiles, filtered to nationality = Japan, refreshed as new profiles are added. You can browse the same underlying data through our public articles API.
The full list
| Fighter | Weight class | Promotion | Sport | Record (W-L-D) | Status | Title |
|---|---|---|---|---|---|---|
| Masaaki Noiri | Featherweight | ONE | Kickboxing | 51-14-0 | Active | Former 2-division K-1 champion |
| Shinya Aoki | Lightweight | ONE | MMA | 49-12-0 | Active | Former 2x ONE Lightweight World Champion |
| Takeru Segawa | Flyweight | ONE | Kickboxing | 46-5-0 | Retired | K-1 three-division champion |
| Shoko Sato | Bantamweight | RIZIN | MMA | 39-17-2 | Active | 10th Shooto World Bantamweight Champion (2017-2020) |
| Koki Osaki | Bantamweight | RISE | Kickboxing | 39-6-1 | Active | RISE World Bantamweight Champion |
| Kyoji Horiguchi | Flyweight | UFC | MMA | 36-7-0 | Active | Former RIZIN Bantamweight Champion |
| Shiro | Bantamweight | RISE | Kickboxing | 35-7-4 | Active | Inaugural RISE World Bantamweight Champion |
| Taiju Shiratori | Super Lightweight | RISE | Kickboxing | 33-13-1 | Active | Current RISE Super Lightweight Champion |
| Naoya Inoue | Super Bantamweight | Boxing | Boxing | 33-0-0 | Active | Undisputed Super Bantamweight Champion (WBA/WBC/IBF/WBO) |
| Junto Nakatani | Super Bantamweight | Boxing | Boxing | 32-1-0 | Active | Former WBO Bantamweight Champion |
| Kenshiro Teraji | Flyweight | Boxing | Boxing | 25-2-0 | Active | Former two-division (light-fly / flyweight) champion |
| Yuki Yoza | Bantamweight | ONE | Kickboxing | 23-3-0 | Active | Former K-1 Lightweight (-62.5kg) Champion |
| Kai Asakura | Flyweight | UFC | MMA | 23-6-0 | Active | Former 2x RIZIN Bantamweight Champion |
| Juntaro Ushiku | Featherweight | RIZIN | MMA | 22-12-0 | Active | 2nd RIZIN Featherweight Champion |
| Kan Nakamura | Lightweight | RISE | Kickboxing | 22-5-1 | Active | 8th RISE Lightweight Champion |
| Takuma Inoue | Bantamweight | Boxing | Boxing | 22-2-0 | Active | WBC Bantamweight Champion |
| Yuki Ito | Flyweight | RIZIN | MMA | 21-7-0 | Active | Inaugural THE OUTSIDER 50-55kg Champion |
| Yutaka Saito | Featherweight | RIZIN | MMA | 21-9-2 | Active | Inaugural RIZIN Featherweight Champion |
| Joji Goto | Bantamweight | RIZIN | MMA | 20-9-0 | Active | |
| Koji Takeda | Featherweight | RIZIN | MMA | 20-8-0 | Active | 9th DEEP Lightweight Champion (October 27, 2018) |
| Mikuru Asakura | Featherweight | RIZIN | MMA | 20-7-0 | Active | RIZIN featherweight contender |
| Kazumasa Majima | Featherweight | RIZIN | MMA | 19-7-0 | Active | |
| Tatsuro Taira | Flyweight | UFC | MMA | 18-2-0 | Active | |
| Ryo Sakai | Heavyweight | DEEP | MMA | 15-16-0 | Active | Former interim DEEP Megaton Champion (November 2022) |
| Rui Okubo | Super Bantamweight | K-1 | Kickboxing | 14-2-0 | Active | Inaugural Krush Flyweight Champion |
| Kyoma Akimoto | Featherweight | RIZIN | MMA | 13-1-0 | Active | |
| Chihiro Suzuki | Featherweight | RIZIN | MMA | 13-6-0 | Active | Former RIZIN Featherweight Champion |
| Seiya Tsutsumi | Bantamweight | Boxing | Boxing | 13-0-3 | Active | WBA Bantamweight Champion |
| Jinnosuke Kashimura | Bantamweight | RIZIN | MMA | 12-6-0 | Active | |
| Yoshiki Takei | Bantamweight | Boxing | Boxing | 12-1-0 | Active | Former WBO Bantamweight Champion |
| Rei Tsuruya | Flyweight | UFC | MMA | 11-1-0 | Active | 8th King of Pancrase Flyweight Champion (2022, later vacated… |
| Shota Yamaguchi | Cruiserweight | K-1 (also GLADIATOR KICK, Krush) | Kickboxing | 11-4-0 | Active | RKS Cruiserweight Champion |
| Taiga Iwasaki | Middleweight | Shooto | MMA | 11-2-0 | Active | Shooto World Middleweight Champion (2026–present) |
| Tsuyoshi Sudario | Heavyweight | RIZIN | MMA | 10-4-0 | Active | |
| Arata Mizuno | Featherweight | DEEP | MMA | 9-2-0 | Active | DEEP interim featherweight title (won May 4, 2026) |
| Tenshin Nasukawa | Bantamweight | Boxing | Boxing | 8-1-0 | Active | Undefeated 42-0 in kickboxing (before switching) |
| Mikio Ueda | Heavyweight | RIZIN | MMA | 5-4-0 | Active | Kyokushin 12th World Karate Championship winner (2019) |
| Ryoma Shishimoto | Flyweight | RIZIN | MMA | 4-1-0 | Active | |
| Naoki Tanaka | Featherweight | RIZIN | MMA | 4-2-0 | Active | 7th RISE lightweight champion (kickboxing) |
| King Edokpolo | Heavyweight | RIZIN | MMA | 4-0-0 | Active | |
| Joe Hiramoto | Flyweight | RIZIN | MMA | 4-2-0 | Active | |
| Ayaka Watanabe | Women's Super Atomweight | Shooto | MMA | 4-3-0 | Active | Shooto World Women's Super Atomweight Champion (since May 20… |
| Ren Hiramoto | Featherweight | RIZIN | MMA | 4-3-0 | Active | |
| Issa Hosokawa | Lightweight | RIZIN | MMA | 0-1-0 | Active | 2nd BreakingDown lightweight champion (2025) |
Sorted by career wins. "Title" marks a fighter who currently holds or has previously held a recognized title — see each fighter's own page for the specific belt and date.
What this doesn't cover yet
This is not every Japanese fighter competing professionally — it's every Japanese fighter with a KIAI profile, which currently skews toward main-card and title-relevant names (see our editorial policy for how we prioritize which fighters get a profile first). Undercard and regional fighters are added on an ongoing basis, and this page updates automatically as they are.
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Cite this data: KIAI (kiai.news), "Japanese Fighters Database," as of August 21, 2026. Compiled from 44 verified fighter profiles.
Sources
FAQ
- How many Japanese fighters are in KIAI's database?
- 44, as of August 21, 2026, spanning MMA, kickboxing, and boxing — filtered from KIAI's full fighter profile database by nationality.
- What is the combined record of the Japanese fighters KIAI tracks?
- 850 wins, 223 losses, and 14 draws across all 44 fighters, machine-totaled from each fighter's individually verified record.
- How many of these fighters hold or have held a title?
- 34 of 44 — about 77% — ranging from undisputed world titles to regional and interim belts across nine promotions.
- Is this every Japanese fighter competing professionally?
- No. It covers every Japanese fighter with a KIAI profile, which currently prioritizes main-card and title-relevant fighters. The list grows as more profiles are added.