| Momo Koseki 関桃 | |
| Weight: | |
| Height: | 5 ft 4 in |
| Reach: | 64 in |
| Nationality: | Japanese |
| Birth Date: | 1982 7, df=y |
| Birth Place: | Tokyo, Japan |
| Style: | Southpaw |
| Total: | 27 |
| Wins: | 24 |
| Ko: | 9 |
| Losses: | 2 |
| Draws: | 1 |
is a Japanese former professional boxer. She is a two-weight world champion, having held the WBC female atomweight title from 2008 to 2015; the WBA female atomweight title in 2015; and the WBC female strawweight title in 2017. Koseki made a record-breaking seventeen consecutive title defenses of her WBC atomweight title.
Koseki was inspired to take up boxing after watching Hiroshi Kawashima on TV. Koseki won the inaugural All-Japan women's amateur championships in 2003, as well as the second edition in 2004. After winning a third national amateur title in 2007, she decided to turn pro as women's boxing was not yet accepted as an Olympic sport.[1]
Koseki won her first three bouts. She went on to challenge Winyu Paradorngym for the inaugural WBC atomweight world title. Winyu won the fight by unanimous decision.[2] In her next fight, Koseki moved up two weight classes to challenge for the WBC light flyweight title, but lost again by unanimous decision.[3] In August 2008, Koseki rematched Paradorngym, and won the title with a round 2 knockout at Korakuen Hall. In August 2014, Koseki made her fourteenth consecutive defense, beating Denise Castle with a round 8 technical knockout. With the win, Koseki broke Yoko Gushiken's Japanese national record of 13 consecutive successful world title defenses.[4] In October 2015, Koseki beat WBA champion Ayaka Miyao by unanimous decision to make her sixteenth defense and unify titles.[5]
Koseki won the WBC minimumweight title on 17 December 2017, defeating reigning champion Yuko Kuroki by decision.[6]
She retired on 29 January 2018, at the age of 34.[7] [8]
| Result | Record | Opponent | Type | Round, time | Date | Location | Notes | ||
|---|---|---|---|---|---|---|---|---|---|
| 27 | Win | 24–2–1 |  Yuko Kuroki | UD | 10 | 17 Dec 2017 | | ||
| 26 | Win | 23–2–1 | Chie Higano | TKO | 4 (10), | 11 Nov 2016 | | ||
| 25 | Win | 22–2–1 |  Rungnapha Kaewkrachang | TKO | 1 (8), | 13 Aug 2016 | | ||
| 24 | Win | 21–2–1 | Ayaka Miyao | UD | 10 | 22 Oct 2015 | | ||
| 23 | Win | 20–2–1 | Aisah Alico | KO | 2 (10), | 19 Feb 2015 | | ||
| 22 | Win | 19–2–1 | Denise Castle | TKO | 8 (10), | 2 Aug 2014 | | ||
| 21 | Win | 18–2–1 | Angor Onesongchaigym | TKO | 9 (10), | 3 Mar 2014 | | ||
| 20 | Win | 17–2–1 |  Nora Cardoza | UD | 10 | 14 Nov 2013 | | ||
| 19 | Win | 16–2–1 |  Eun Young Huh | TKO | 6 (10), | 28 May 2013 |  | ||
| 18 | Win | 15–2–1 | Maria del Refugio Jimenez Cruz | UD | 10 | 3 Mar 2013 | | ||
| 17 | Win | 14–2–1 | Saemi Hanagata | UD | 10 | 17 Dec 2012 | | ||
| 16 | Win | 13–2–1 | Jujeath Nagaowa | UD | 10 | 19 Jun 2012 | | ||
| 15 | Win | 12–2–1 | Mami Ito | 10 (10), | 30 Nov 2011 | | |||
| 14 | Win | 11–2–1 | Krikanok Islandmuaythai | TKO | 5 (10), | 8 May 2011 | | ||
| 13 | Draw | 10–2–1 | Masae Akitaya | 3 (10), | 6 Jun 2010 | | |||
| 12 | Win | 10–2 | Gun Joo Shin | UD | 10 | 27 Mar 2010 | | ||
| 11 | Win | 9–2 | Teeraporn Pannimit | UD | 10 | 29 Nov 2009 | | ||
| 10 | Win | 8–2 | Nao Ikeyama | UD | 10 | 2 May 2009 | | ||
| 9 | Win | 7–2 | Hye-Min Kim | UD | 10 | 8 Dec 2008 | | ||
| 8 | Win | 6–2 | Chirawadee Srisuk | 2 (10), | 11 Aug 2008 | | |||
| 7 | Win | 5–2 | Petchsifah Sithkrumad | 2 (6), | 9 Jun 2008 | | |||
| 6 | Win | 4–2 | Mayumi Kubo | UD | 4 | 9 May 2008 | | ||
| 5 | Loss | 3–2 | Siriporn Taweesuk | UD | 10 | 19 Nov 2007 | | ||
| 4 | Loss | 3–1 | Chirawadee Srisuk | UD | 10 | 31 Aug 2007 | | ||
| 3 | Win | 3–0 | Singsamaoy Sitnhongalampoon | 6 | 7 Jul 2007 | | |||
| 2 | Win | 2–0 | Teeraporn Pannimit | UD | 6 | 16 Jun 2007 | | ||
| 1 | Win | 1–0 | Yupin Ha Payak | 4 | 26 May 2007 | |