Natsumi Kawaguchi

Natsumi Kawaguchi
川口夏実
Country (sports)	Japan
Born	28 June 2002; Nagasaki Prefecture, Japan
Height	1.63 m (5 ft 4 in)
Plays	Left (two-handed backhand)
Prize money	$89,763
Singles
Career record	155–99
Career titles	4 ITF
Highest ranking	No. 346 (9 October 2023)
Current ranking	No. 384 (27 July 2026)
Doubles
Career record	108–78
Career titles	7 ITF
Highest ranking	No. 230 (29 June 2026)
Current ranking	No. 230 (27 July 2026)
	Last updated on: 31 July 2026.

Natsumi Kawaguchi (川口夏実, Kawaguchi Natsumi; born 28 June 2002) is a Japanese tennis player.^[3]

On 9 October 2023, she has achieved career-high rankings of 346 in singles, and on 29 June 2026 of 230 in doubles.

Kawaguchi and her partner Adrienn Nagy won the 2019 Australian girls' doubles title, beating Emma Navarro and Chloe Beck in the final.^[4]^[5]

She qualified for the main draw of the WTA 500 2023 Pan Pacific Open at home in Tokyo but had to withdraw shortly after.

ITF Circuit finals

Singles: 6 (4 titles, 2 runner-ups)

Legend
W60 tournaments
W35 tournaments
W15 tournaments

Result	W–L	Date	Tournament	Tier	Surface	Opponent	Score
Win	1–0	Apr 2019	ITF Cancún, Mexico	W15	Hard	Emily Appleton	7–6⁽²⁾, 6–7⁽²⁾, 6–3
Loss	1–1	Oct 2021	ITF Monastir, Tunisia	W15	Hard	Tamira Paszek	2–6, 3–6
Win	2–1	Mar 2023	ITF Hinode, Japan	W15	Hard	Aoi Ito	6–4, 6–3
Win	3–1	Apr 2023	ITF Osaka, Japan	W15	Hard	Miho Kuramochi	6–4, 6–1
Win	4–1	May 2023	Fukuoka International, Japan	W60	Carpet	Katie Boulter	w/o
Loss	4–2	Oct 2025	Brisbane QTC International, Australia	W35	Hard	Taylah Preston	2–6, 4–6

Doubles: 16 (7 titles, 9 runner-ups)

Legend
W75 tournaments
W40/50 tournaments
W25/35 tournaments
W15 tournaments

Result	W–L	Date	Tournament	Tier	Surface	Partner	Opponents	Score
Win	1–0	Apr 2019	ITF Cancún, Mexico	W15	Hard	Maya Tahan	Emily Appleton María Portillo Ramírez	6–1, 6–2
Loss	1–1	Dec 2019	ITF Cancún, Mexico	W15	Hard	Nika Kukharchuk	Madison Appel Elle Christensen	w/o
Loss	1–2	Jun 2023	ITF Tokyo, Japan	W25	Hard	Talia Gibson	Luksika Kumkhum Kanako Morisaki	6–1, 2–6, [3–10]
Loss	1–3	Jul 2023	ITF Hong Kong, China	W40	Hard	Kanako Morisaki	Eudice Chong Cody Wong	5–7, 4–6
Win	2–3	Oct 2023	ITF Hamamatsu, Japan	W25	Carpet	Hiromi Abe	Haruna Arakawa Aoi Ito	3–6, 6–4, [10–4]
Loss	2–4	Dec 2023	ITF Yokohama, Japan	W40	Hard	Aoi Ito	Liang En-shuo Tang Qianhui	w/o
Win	3–4	Aug 2024	ITF Nakhon Si Thammarat, Thailand	W15	Hard	Momoko Kobori	Honoka Kobayashi Yukina Saigo	6–3, 6–4
Loss	3–5	Aug 2024	ITF Nakhon Si Thammarat, Thailand	W35	Hard	Momoko Kobori	Kanako Morisaki Hikaru Sato	2–6, 3–6
Loss	3–6	Jul 2025	ITF Nakhon Pathom, Thailand	W15	Hard	Haruna Arakawa	Kim Na-ri Ye Qiuyu	3–6, 2–6
Win	4–6	Aug 2025	ITF Singapore	W15	Hard	Haruna Arakawa	Natsuho Arakawa Anri Nagata	6–2, 6–2
Loss	4–7	Sep 2025	ITF Nakhon Pathom, Thailand	W35	Hard	Erika Sema	Mana Ayukawa Eri Shimizu	2–6, 7–6⁽⁵⁾, [8–10]
Win	5–7	Sep 2025	ITF Yeongwol, South Korea	W15	Hard	Kim Da-bin	Ha Sun-min Shek Cheuk-ying	6–4, 6–2
Win	6–7	Oct 2025	Brisbane QTC International, Australia	W35	Hard	Monique Barry	Tenika McGiffin Naho Sato	7–5, 6–3
Loss	6–8	Nov 2025	Yokohama Challenger, Japan	W50	Hard	Hayu Kinoshita	Dang Yiming You Xiaodi	6–2, 3–6, [4–10]
Win	7–8	Feb 2026	Queensland International, Australia	W75	Hard	Sara Saito	Gabriella Da Silva-Fick Tenika McGiffin	6–2, 6–4
Loss	7–9	Jun 2026	ITF Taipei, Taiwan	W35	Hard	Ayano Shimizu	Back Da-yeon Tsao Chia-yi	5–7, 1–6