Keiichiro Matsui
Keiichiro Matsui is a Japanese badminton player who affiliated with the Hitachi team. Born in Ishikawa, he graduated from the Tomioka senior high school, and later educated at the Nippon Sport Science University. He was part of the national junior team that won the gold medal at the 2012 Asian Junior Championships, and the silver medal at the 2012 World Junior Championships.
Achievements
BWF World Tour (1 runner-up)
The BWF World Tour, announced on 19 March 2017 and implemented in 2018, is a series of elite badminton tournaments, sanctioned by Badminton World Federation. The BWF World Tour are divided into six levels, namely World Tour Finals, Super 1000, Super 750, Super 500, Super 300, and the BWF Tour Super 100.Men's doubles
| Year | Tournament | Level | Partner | Opponent | Score | Result |
| 2019 | Russian Open | Super 100 |  Yoshinori Takeuchi |  Mathias Boe Mads Conrad-Petersen | 18–21, 13–21 | Runner-up |
BWF Grand Prix (1 runner-up)
The BWF Grand Prix has two levels, the BWF Grand Prix and Grand Prix Gold. It is a series of badminton tournaments sanctioned by the Badminton World Federation since 2007.Mixed doubles
| Year | Tournament | Partner | Opponent | Score | Result |
| 2017 | Russian Open | Akane Araki |  Chan Peng Soon Cheah Yee See | 8–11, 13–11, 3–11 | Runner-up |
BWF International Challenge/Series (2 titles, 1 runner-up)
Men's doubles| Year | Tournament | Partner | Opponent | Score | Result |
| 2019 | Dubai International | Yoshinori Takeuchi | Shia Chun Kang Tan Boon Heong | 21–14, 21–14 | Winner |
| 2019 | Maldives International | Yoshinori Takeuchi |  Arun George Sanyam Shukla | 21–9, 22–20 | Winner |
| 2017 | Spanish International | Yoshinori Takeuchi |  Jacco Arends Ruben Jille | 17–21, 19–21 | Runner-up |