|Born||29 April 1991|
|Height||1.59 m (5 ft 3 in)|
|Plays||Left-handed (two-handed backhand)|
|Prize money||US$ 3,095,065|
|Career record||359-322 (52.7%)|
|Highest ranking||No. 30 (10 October 2016)|
|Current ranking||No. 77 (5 April 2021)|
|Grand Slam Singles results|
|Australian Open||2R (2013)|
|French Open||2R (2015)|
|US Open||2R (2015)|
|Career record||125-104 (54.6%)|
|Highest ranking||No. 78 (6 October 2014)|
|Current ranking||No. 83 (5 April 2021)|
|Grand Slam Doubles results|
|Australian Open||2R (2020)|
|French Open||2R (2013, 2020, 2021)|
|Wimbledon||2R (2017, 2021)|
|US Open||2R (2017)|
|Fed Cup||31-10 (75.6%)|
|Last updated on: 5 April 2021.|
Doi reached two junior Grand Slam doubles finals - at Wimbledon in 2007 with Kurumi Nara, and at the Australian Open in 2008, with Elena Bogdan (losing both). She has made it to three WTA tournament finals (only winning one). She is managed by Muse Group, a sports marketing agency based in Tokyo.
Doi began playing tennis at the age of three. She first distinguished herself in tennis as a middle-school student, reaching the semifinals of the All Japan Middle School Tennis Championships in both 2004 and 2006 and joining the ITF Junior Circuit in 2006. In 2007, while enrolled as a freshman in Sundai K?ei High School, Doi earned second place in the Japan Open Junior Championships in Nagoya.
A highlight of Doi's junior career was her successful doubles partnership with age-mate Kurumi Nara. They placed second in girls' doubles at the 2007 Wimbledon Championships, becoming only the second Japanese pair to reach the finals of a Grand Slam juniors event since Yuka Yoshida and Hiroko Mochizuki at the 1993 US Open. Doi and Nara continued their run by advancing to the girls' doubles semifinals at a number of high-profile tournaments, such as the 2007 US Open and Wimbledon 2008. Doi also teamed with Romanian Elena Bogdan to place second in girls' doubles at the 2008 Australian Open. This flurry of successes catapulted Doi to No. 3 in Japan's under-18 tennis rankings for 2007; she had been recognized early on as one of Japan's rising stars in junior tennis.
2008 marked Doi's first participation in ITF Women's Circuit events. She partnered with Kurumi Nara again for the 2008 ITF event in Miyazaki, where they upset top-seeded sisters Erika and Yurika Sema, 3-6, 6-3, [10-6] in the second round. Doi and Nara went on to triumph over Kimiko Date-Krumm and Tomoko Yonemura in the finals.
Doi officially turned pro in June 2006, at the age of 15. In 2009, she focused primarily on Japanese tournaments, where she earned two first-place and two second-place finishes in singles and one second-place result in doubles. In March 2009, she won her first ITF title at the $10k Kofu event. In October, she made her tour debut in the qualifiers of the Japan Open, falling to American Abigail Spears in the second qualifying round. Doi was seeded sixth in the women's singles draw of the All Japan Tennis Championships. She lost in straight sets to Akiko Morigami in the round of 16. Her performance in 2009's events lifted Doi from a year-opening ranking of No. 613 to a year-end mark of No. 199 and a place among the top 10-players in Japanese tennis.
In 2010, Doi began playing professional tournaments outside Japan. She appeared in the women's singles qualifiers for that year's Australian Open. Doi then made appearances at several circuit tournaments, placing second in singles at Irapuato, Mexico in March. In doubles, she recorded three second-place finishes in as many weeks in April tournaments at Incheon, Gimhae, and Changwon, South Korea, with partner Junri Namigata. With new partner Kotomi Takahata, Doi won her first $50k title in doubles at the Fukuoka International in May, defeating Marina Erakovic and Alexandra Panova in straight sets.
Her success continued in the qualifying rounds of the French Open, where she defeated Mandy Minella and upset Michelle Larcher de Brito to reach the qualifier finals. With her victory over Vitalia Diatchenko, Doi had earned a spot in her first major tournament main draw, where she lost to Polona Hercog in the first round. She finished the year with a first-place performance in the All Japan Tennis Championships women's singles.
Doi's Grand Slam results improved in 2011, when she qualified for Wimbledon and had her first win in Grand Slam tournament against Bethanie Mattek-Sands. She went on to defeat Zheng Jie before losing in the third round to Sabine Lisicki.
The Aegon Classic was Doi's first appearance in the quarterfinals of a singles tour event, which she reached by defeating the top seed Francesca Schiavone in two sets. Although Doi lost in the Wimbledon qualifiers to Kristina Mladenovic, she received a lucky loser berth in the main tournament. She was defeated by her first-round opponent Arantxa Rus.
After failing to qualify for the main draws of the US Open and Pan Pacific Open, Doi found success at the Japan Open, where she defeated Chanelle Scheepers in three sets to reach her first tour semifinal.
2013 marked the first year in which Doi qualified for all four Grand Slam tournaments. In the Australian Open, she reached the second round after a two-set victory over Petra Marti? before losing 0-6, 0-6 to Maria Sharapova. She lost in the first round in the other three Grand Slam events. At the French Open she faced Madison Keys; at Wimbledon Sílvia Soler Espinosa; and at the US Open Petra Kvitová.
At the Australian Open, Doi played the seventh seed Angelique Kerber in the first round, winning the first set and holding a match point in the second-set tie-break before eventually losing in three sets. Kerber went on to win the title. On 16 May, she achieved a new career-high ranking of 38 after a quarterfinal appearance in Rome. Doi then competed at the Birmingham Classic, losing to Johanna Konta. Doi reached the last 16 of Wimbledon, beating Louisa Chirico, Karolína Plí?ková and Anna-Lena Friedsam before losing to Kerber in straight sets. She was the first Japanese player to reach the fourth round of the ladies draw since Ai Sugiyama ten years earlier.
Doi is coached by Christian Zahalka since April 2015. Her most admired players are Justine Henin and Shingo Kunieda. She uses a Srixon racquet and ASICS shoes, prefers to play on hard courts, and favors her forehand and serve.
Only main-draw results in WTA Tour, Grand Slam tournaments, Fed Cup/Billie Jean King Cup and Olympic Games are included in win/loss records.
Current after the 2020 Summer Olympics.
|Australian Open||1R||1R||A||1R||1R||3R||1R||0 / 6||2-6||25%|
|French Open||2R||A||A||2R||1R||2R||2R||0 / 5||4-5||44%|
|Wimbledon||A||A||1R||2R||2R||NH||0 / 3||2-3||40%|
|US Open||A||2R||A||1R||2R||A||0 / 3||2-3||40%|
|Win-Loss||1-2||1-2||0-1||2-4||2-4||3-2||1-2||0 / 17||10-17||37%|
|Win||1-0||Oct 2015||Luxembourg Open||International||Hard (i)||Mona Barthel|
|Loss||1-1||Taiwan Open||International||Hard||4-6, 2-6|
|Loss||1-2||Sep 2019||Japan Open||International||Hard||Nao Hibino||3-6, 2-6|
|Win||1-0||Jul 2014||?stanbul Cup, Turkey||International||Hard||Elina Svitolina|| Oksana Kalashnikova
|Loss||1-1||Sep 2015||Japan Open||International||Hard||Kurumi Nara|| Chan Yung-jan
|Win||2-1||Sep 2019||Japan Open||International||Hard||Nao Hibino|| Christina McHale
|3-6, 6-4, [10-4]|
|Loss||0-1||Nov 2015||Taipei Open, Taiwan||Carpet (i)||Tímea Babos||5-7, 3-6|
|Win||1-1||Mar 2016||San Antonio Open, United States||Hard||Anna-Lena Friedsam||6-4, 6-4|
|Win||2-1||Jul 2019||Båstad Open, Sweden||Clay||Danka Kovini?||6-4, 6-4|
|Loss||2-2||Mar 2020||Indian Wells Challenger, U.S.||Hard||Irina-Camelia Begu||3-6, 3-6|
|Win||1-0||Nov 2013||Nanjing Open, China||Hard||Xu Yifan|| Zhang Shuai
|Win||2-0||Jan 2018||Newport Beach Challenger, U.S.||Hard||Jil Teichmann|| Jamie Loeb
|7-6(7-4), 1-6, [10-8]|
|Win||3-0||Jul 2019||Båstad Open, Sweden||Clay||Natalia Vikhlyantseva|| Alexa Guarachi
|7-5, 6-7(4-7), [10-7]|
|Win||1-0||Mar 2009||K?fu International Open, Japan||10,000||Hard||Erika Sema||7-5, 6-2|
|Win||2-0||Jul 2009||ITF Tokyo, Japan||10,000||Carpet||Sachie Ishizu||6-1, 6-4|
|Loss||2-1||Sep 2009||ITF Makinohara, Japan||25,000||Carpet||Hsieh Su-wei||6-2, 5-7, 6-7(4)|
|Loss||2-2||Oct 2009||ITF Tokachi, Japan||25,000||Carpet||Tomoko Yonemura||4-6, 6-7(3)|
|Loss||2-3||Mar 2010||ITF Irapuato, Mexico||25,000||Hard||Monique Adamczak||6-7(5), 6-2, 2-6|
|Win||3-3||Nov 2010||ITF Toyota, Japan||75,000||Carpet (i)||Junri Namigata||7-5, 6-2|
|Win||4-3||Apr 2014||ITF Seoul, South Korea||50,000||Hard||Misa Eguchi||6-1, 7-6(3)|
|Win||5-3||Jan 2015||ITF Hong Kong, China SAR||50,000||Hard||Zhang Kailin||6-3, 6-3|
|Win||6-3||Aug 2018||Vancouver Open, Canada||100,000||Hard||Heather Watson||6-7(4), 6-1, 6-4|
|Win||1-0||Jul 2008||ITF Miyazaki, Japan||25,000||Carpet||Kurumi Nara|| Kimiko Date-Krumm
|4-6, 6-3, [10-7]|
|Loss||1-1||May 2009||Kangaroo Cup Gifu, Japan||50,000||Carpet||Kurumi Nara|| Sophie Ferguson
|Loss||1-2||Apr 2010||ITF Incheon, South Korea||25,000||Hard||Junri Namigata|| Irina-Camelia Begu
|Loss||1-3||Apr 2010||ITF Gimhae, South Korea||25,000||Hard||Junri Namigata|| Chang Kyung-mi
|6-1, 4-6, [8-10]|
|Loss||1-4||Apr 2010||ITF Changwon, Korea||25,000||Hard||Junri Namigata|| Chang Kyung-mi
|7-5, 3-6, [8-10]|
|Win||2-4||May 2010||Fukuoka International, Japan||50,000||Grass||Kotomi Takahata|| Marina Erakovic
|Loss||2-5||Jul 2013||Beijing International, China||75.000||Hard||Miki Miyamura|| Liu Chang
|Win||3-5||Nov 2013||ITF Toyota, Japan||75.000||Carpet (i)||Shuko Aoyama|| Eri Hozumi
|7-6(1), 2-6, [11-9]|
|Loss||3-6||May 2014||ITF Gifu, Japan||75.000||Hard||Hsieh Shu-ying|| Jarmila Gajdo?ová
|Win||4-6||Feb 2018||ITF Surprise, United States||25,000||Hard||Yanina Wickmayer|| Jacqueline Cako
|2-6, 6-3, [10-8]|
|1.||Madison Keys||No. 10||Madrid Open, Spain||Clay||1st round||6-4, 4-6, 6-4|