Kobayashi Izumi

Kobayashi Izumi (小林 泉美, b. 20 June 1977) is a Japanese, professional 7-dan born in Tokyo, Japan. She is a member of the Nihon Ki-in.

Kobayashi Izumi has won 12 titles, 5th place in the number of women’s titles. In 2004, she and her new husband Cho U were called the “Honinbo Couple”, because Cho was Honinbo and Kobayashi Female Honinbo.

On the World Women's Rating Lists of 2003-01-01 to 2005-01-01, Kobayashi Izumi was the #1 Japanese woman. Her best women’s world ranking was #10, on the 1997-01-01 list

Kobayashi has an overall professional game record of 949 games, 544 wins, and 405 losses, for a 57.3% win rate (as of 2025/03/18).

Table of contents Family Go career Promotion history Titles Runners-up Head-to-head scores against current female rivals Views on male and female players Links Photos Notes

Family

Izumi is the daughter of Kobayashi Koichi and Kobayashi Reiko (née Kitani), and the granddaughter of Kitani Minoru. Izumi’s first Go teacher was her mother. Her father was originally opposed, but later on became her other main teacher. Izumi joked that she learned Go in her mother’s womb. Her two daughters, now also Go professionals, could say the same.

On 9 Nov 2003, she became engaged to Cho U, and they were married on 12 Jan 2004 in Okinawa. Shortly after the wedding, Cho thought that their active Go careers would leave little time to have babies. Evidently he soon changed his mind.

Kobayashi gave birth to her first daughter Cho Kosumi on 24 Mar 2006, and won the 6th Female Strongest while pregnant with her. Kobayashi bore her second daughter Cho Koharu on 10 Nov 2009. Like her mother before her, at the top of her career as one of the best female Go players in Japan, she suspended her career to support her husband and raise their children. Because her own mother Reiko had died so young, Izumi could not be like many new mothers who rely on their own mothers for help and guidance. Reiko did live long enough to see Izumi become a professional.

After her youngest daughter followed in her older sister’s footsteps and became a professional on 1 April 2022, Kobayashi returned to professional Go that year.

Go career

In 2001, she became the first player to hold two women’s titles (Women's Honinbo and Women's Meijin) simultaneously, as well as the first player to hold the three major women's titles simultaneously (Women's Kisei, Women's Honinbo, Women's Meijin).

After a long hiatus to raise her daughters and support her husband’s Go career, she returned to her winning ways. On 25 February 2024, she won her first major title in 19 years (16 years after the quickplay Daiwa Ladies Cup), to the delight of her many admirers, when she defeated Koyama Terumi in the final of 3rd Teikei Cup Female Legends. The game was up-and-down, but Kobayashi eventually won with a clamp that killed a big dragon (W+R). Next year, she repeated her victory in the 4th Teikei Cup Female Legends. She beat Osawa Narumi in the final on 12 Apr (W+15.5).

Promotion history

Professional 1 dan 1995, 2 dan 1997, 3 dan 1998, 4 dan 1999, 5 dan 2001, 6 dan in 2004, 7 dan 2021.

Titles

• 1998: 1st Women's Kisei
• 1999: 2nd Women's Kisei
• 2001: 13th Women's Meijin
• 2001: 20th Women's Honinbo
• 2002: 21st Women's Honinbo
• 2003: 15th Women's Meijin
• 2003: 22nd Women's Honinbo
• 2004: 16th Women's Meijin
• 2004: JAL Female HayaGo
• 2005: 6th Female Strongest
• 2007: 1st Daiwa Ladies Cup
• 2023–4: 3rd Teikei Cup Female Legends
• 2024–5: 4th Teikei Cup Female Legends

Runners-up

• 1996: 17th Women's Kakusei
• 1999: 18th Women's Honinbo
• 1999: 20th Women's Kakusei
• 2000: 3rd Women's Kisei
• 2000: 12th Women's Meijin
• 2001: 22nd Women's Kakusei
• 2002: 14th Women's Meijin
• 2004: 22nd Women's Honinbo

Head-to-head scores against current female rivals

(Based on Kobayashi Izumi, Go Ratings and game list), as of 3 Apr 2025.

• Sugiuchi Kazuko, 8p, 4× All-Japan Women's Championship, 4× Women's Meijin, 2× Women's Kakusei: 4–2
• Konishi Kazuko, 8p, once Kansai Ladies' Tournament, once Teikei Cup Female Legends: 4–2
• Kusunoki Teruko, 8p, Sugiuchi Kazuko's youngest sister, 5× Female Honinbo, 3× Women's Kakusei: 3–0
• Yoshida Mika, 8p, 4× Women's Honinbo, 4× Kansai Ladies' Tournament, once Women's Kakusei: 5–3
• Aoki Kikuyo, 8p, 5× Women's Meijin, 4× Women's Kakusei, once Female Kisei: 10–6
• Yashiro Kumiko, 6p, 2× Women's Honinbo, 5–3
• Ueno Asami, 6p, according to rating list, #5 female and #200 overall in the world, and #1 female and #27 overall in Japan: 0–3
• Fujisawa Rina, 7p, #9 female in world, #2 female in Japan: 0–1
• Xie Yimin, 7p, #30 ranked female in the world, #5 ranked female in Japan (many years #1): 2–6
• Ueno Risa, 3p, Asami's younger sister, #21 female and #3 female teenager in world, #3 female in Japan, Female Kisei: 0–1
• Nakamura Sumire, 4p, #14 female and #3 female teenager in the world, #3 ranked female in Japan, #5 ranked female in Korea: 1–1
• Nyu Eiko, 4p, 2× Female Strongest: 2–1
• Ogawa Tomoko, 7p, once Female Honinbo, 2× All-Japan Women's Championship: 2–1
• Kato Keiko, 6p, once Women's Meijin, once Female Strongest: 4–5
• Kato Tomoko, 6p, once Women's Honinbo, Women's Meijin, Women's Kakusei, and Female Strongest: 4–3
• Umezawa Yukari, 6p, 3× Female Kisei: 5–4
• Kobayashi Chizu, 6p, 3× Women's Kakusei and All-Japan Women's Championship: 2–0
• Chinen Kaori, 6p, 5× Female Kisei, 4× Women's Honinbo: 9–13
• Mukai Chiaki, 6p, once Women's Honinbo: 2–3
• Koyama Terumi, 6p, 4× Women's Meijin: 3–3
• Mukai Chiaki, 6p, once Women's Honinbo: 9–2
• Mannami Kana, 4p, 2× Female Kisei: 3–3
• Nakazawa Ayako, 5p, 2× Women's Honinbo, Women's Kakusei: 4–2
• Osawa Narumi, 5p, 2× Women's Kakusei: 1–3
• Rui Naiwei, 9p, #18 female in world, many years #1 female in world: 0–2

Views on male and female players

Kobayashi says that Go is a great equalizer and meritocracy:

Q: We feel that there are few women in the Go world but many men. Have you ever suffered in this world?

Kobayashi Izumi: Take the Nihon Ki'in, where I belong, for example. There are 350 players, of which less than 20% are female. This is a little more than 30 years ago when less than 10% were female. Although there are relatively few female players, and it seems like a male society, in fact, in the world of Go, there are still many opportunities for female players to achieve success.

Q: How to put it?

Kobayashi Izumi: There are currently nine mixed-gender tournaments and five tournaments for women, so women have more opportunities to play than men. In addition, there are tournaments for young and veteran players, international tournaments, and many other types of competitions, so the busiest players in the Japanese Go world are young women. In fact, women played the most games and won the most games last year, and women have won many championships in mixed-gender tournaments for young players.

Q: Female chess players have many opportunities to achieve good results, and since it is a world of wins and losses, it is equal.

Kobayashi Izumi: Complete equality. From a gender perspective, I think there is no game more equal than Go when it comes to men, women, young, and old.

Links

• Japanese Wikipedia
• Nihon Ki'in profile
• Go Ratings and Games
• Go4Go
• Her Twitter/X page

Photos

Kobayashi Izumi with her husband Cho U and younger daughter Cho Koharu after Koharu became a pro, 2022 (Image credit: zhuanlan.zhihu.com

Kobayashi Izumi with her husband Cho U and younger daughter Cho Koharu after Koharu became a pro, 2022 (Image credit: zhuanlan.zhihu.com

Kobayashi Izumi with her husband and two daughters, 2010 (Image credit: vip.udn.com

Notes

• On 29 July 2004, Kobayashi Izumi faced her father Koichi at the 43rd Judan tournament, making the game the first ever father-daughter pro tournament game. They both played a fighting game with her father winning as White in the end.