(born 15 April 1998) is a Japanese professional golfer. She plays on the LPGA of Japan Tour where she has 12 victories.
Career Koiwai was born in Kitahiroshima, Hokkaido in 1998 and started playing golf when she was 8 years old. She won the Hokkaido Amateur Championship in 2014 and 2016.
Koiwai turned professional and joined the LPGA of Japan Tour in 2017. In 2018, she recorded four runner-up finishes to rank 8th on the money list, and won the PGA Rookie of the Year award and the Japan Professional Sports Rookie of the Year award.
She captured the 2019 Samantha Thavasa Girls Collection Ladies Tournament for her maiden win on the JLPGA. Her lone victory in 2020 was the Golf5 Ladies.
In 2021, Koiwai recorded four wins and three second-place finishes, to finish 3rd on the 2020–21 money list with over 200 million yen in season earnings.
In mid-2021, she rose into the top-50 in the Women's World Golf Rankings for the first time.
Amateur wins 2014 Hokkaido Amateur Championship 2016 Hokkaido Amateur Championship
Source:
Professional wins (12) LPGA of Japan Tour wins (12) No.DateTournamentWinning scoreTo parMargin ofvictoryRunner(s)-up121 Jul 2019Samantha Thavasa Girls Collection Ladies Tournament66-68-65=199−171 stroke Lee Min-young226 Sep 2020Golf5 Ladies68-65-66=199−17 6 strokes Ayaka Furue Ayake Watanabe 37 Mar 2021Daikin Orchid Ladies Golf Tournament71-69-66-68=274−141 stroke Haruka Morita-WanyaoLu421 Mar 2021T-Point ENEOS Golf Tournament68-68-70=206−102 strokes Bae Seon-woo Ai Suzuki Tsai Pei-ying515 Aug 2021NEC Karuizawa 72 Golf Tournament64-34=98^−102 strokes Tsai Pei-ying622 Aug 2021CAT Ladies68-70-71=209−72 strokes Mone Inami Kana Mikashima Sayaka Takahashi729 May 2022Resort Trust Ladies69-67-64-71=271−172 strokes Nana Suganuma Tsai Pei-ying89 Oct 2022Stanley Ladies Honda Golf Tournament67-67-70=204−171 stroke Kana Nagai Mao Saigo Nana Suganuma99 Jul 2023MinebeaMitsumi Ladies Hokkaido Shimbun Cup69-68-68-71=276−123 strokes Lala Anai Erika Kikuchi1031 Mar 2024Yamaha Ladies Open Katsuragi66-73-67=206−101 stroke Chisato Iwai Rio Takeda1123 Jun 2024Earth Mondahmin Cup70-66-65-71=272−163 strokes Yuka Yasuda1220 Jul 2025Meiji Yasuda Ladies Golf Tournament66-69-66=201−151 stroke Yui Kawamoto Hanane Nagashima Kano Nakamura Miyu Sato ^Tournament shortened due to adverse conditions.
Results in LPGA majors Tournament 2024 2025 2026Chevron ChampionshipU.S. Women's OpenT9T45T60Women's PGA ChampionshipThe Evian ChampionshipWomen's British OpenCUT
CUT = missed the half-way cut "T" = tied
References
External links