Momo Koseki


Momo Koseki 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 is a member of the International Women's Boxing Hall of Fame.

Career

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.
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. In her next fight, Koseki moved up two weight classes to challenge for the WBC light flyweight title, but lost again by unanimous decision. 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. In October 2015, Koseki beat WBA champion Ayaka Miyao by unanimous decision to make her sixteenth defense and unify titles.
Koseki won the WBC minimumweight title on 17 December 2017, defeating reigning champion Yuko Kuroki by decision.
She retired on 29 January 2018, at the age of 34.
In October 2025, Koseki was named among the inductees for the 2026 International Women's Boxing Hall of Fame class.

Professional boxing record

No.ResultRecordOpponentTypeRound, timeDateLocationNotes
27Win24–2–1Yuko KurokiUD1017 Dec 2017Kyuden Gym, Fukuoka, JapanWon WBC female mini-flyweight title
26Win23–2–1Chie HiganoTKO4, 0:3611 Nov 2016Korakuen Hall, Tokyo, JapanRetained WBC female atomweight title
25Win22–2–1Rungnapha KaewkrachangTKO1, 1:4513 Aug 2016City Culture Hall, Soka, Japan
24Win21–2–1Ayaka MiyaoUD1022 Oct 2015Korakuen Hall, Tokyo, JapanRetained WBC female atomweight title;
Won WBA female atomweight title
23Win20–2–1Aisah AlicoKO2, 1:2919 Feb 2015Korakuen Hall, Tokyo, JapanRetained WBC female atomweight title
22Win19–2–1Denise CastleTKO8, 0:292 Aug 2014Adachi Ward Sogo Sports Center, Tokyo, JapanRetained WBC female atomweight title
21Win18–2–1Angor OnesongchaigymTKO9, 1:433 Mar 2014Korakuen Hall, Tokyo, JapanRetained WBC female atomweight title
20Win17–2–1Nora CardozaUD1014 Nov 2013Korakuen Hall, Tokyo, JapanRetained WBC female atomweight title
19Win16–2–1Huh Eun-youngTKO6, 1:2328 May 2013Hong Kong Convention and Exhibition Centre, Wan Chai, ChinaRetained WBC female atomweight title
18Win15–2–1Maria del Refugio JimenezUD103 Mar 2013Korakuen Hall, Tokyo, JapanRetained WBC female atomweight title
17Win14–2–1Saemi HanagataUD1017 Dec 2012Korakuen Hall, Tokyo, JapanRetained WBC female atomweight title
16Win13–2–1Jujeath NagaowaUD1019 Jun 2012Korakuen Hall, Tokyo, JapanRetained WBC female atomweight title
15Win12–2–1Mami Ito10, 0:5330 Nov 2011Korakuen Hall, Tokyo, JapanRetained WBC female atomweight title
14Win11–2–1Krikanok IslandmuaythaiTKO5, 1:158 May 2011Korakuen Hall, Tokyo, JapanRetained WBC female atomweight title
13Draw10–2–1Masae Akitaya3, 2:006 Jun 2010Korakuen Hall, Tokyo, JapanRetained WBC female atomweight title
12Win10–2Shin Gun-jooUD1027 Mar 2010Ariake Colosseum, Tokyo, JapanRetained WBC female atomweight title
11Win9–2Teeraporn PannimitUD1029 Nov 2009Saitama Super Arena, Saitama, JapanRetained WBC female atomweight title
10Win8–2Nao IkeyamaUD102 May 2009Korakuen Hall, Tokyo, JapanRetained WBC female atomweight title
9Win7–2Kim Hye-minUD108 Dec 2008Korakuen Hall, Tokyo, JapanRetained WBC female atomweight title
8Win6–2Chirawadee Srisuk2, 0:4811 Aug 2008Korakuen Hall, Tokyo, JapanWon WBC female atomweight title
7Win5–2Petchsifah Sithkrumad2, 0:549 Jun 2008Korakuen Hall, Tokyo, Japan
6Win4–2Mayumi KuboUD49 May 2008Korakuen Hall, Tokyo, Japan
5Loss3–2Siriporn ThaweesukUD1019 Nov 2007The Mall Shopping Center Ngamwongwan, Bangkok, ThailandFor WBC female light-flyweight title
4Loss3–1Chirawadee SrisukUD1031 Aug 2007The Office of Pak Hai District, Ayutthaya, ThailandFor inaugural WBC female atomweight title
3Win3–0Singsamaoy Sitnhongalampoon67 Jul 2007Bangkok, Thailand
2Win2–0Teeraporn PannimitUD616 Jun 2007Rajamangala Stadium, Bangkok, Thailand
1Win1–0Yupin Ha Payak426 May 2007Rajamangala Stadium, Bangkok, Thailand