Stadium: Court 2 Round: 25 Ground: Hardcourt outdoor
| ITF Japan F2 | 2018/03/12 02:30 | Seong Chan Hong v Shuichi Sekiguchi | 6-4,1-6,7-6 |
| Challenger Yokohama Qual | 2018/02/24 05:10 | Hiroki Moriya v Shuichi Sekiguchi | 6-2,6-4 |
| Challenger Kyoto Qual | 2018/02/17 06:10 | Yuya Kibi v Shuichi Sekiguchi | 6-3,6-2 |
| Challenger Ningbo Qual | 2017/10/15 07:50 | Shuichi Sekiguchi v Yunseong Chung | 4-6,3-6 |
| Challenger Kaohsiung | 2017/10/03 05:40 | Shuichi Sekiguchi v Akira Santillan | 3-6,4-6 |
| Challenger Gwangju | 2017/09/19 01:30 | Shuichi Sekiguchi v Tsung-Hua Yang | 5-7,6-7 |
| Challenger Shanghai | 2017/09/12 06:35 | Alexander Kudryavtsev v Shuichi Sekiguchi | 6-4,4-6,2-6 |
| Challenger Zhangjiagang | 2017/09/07 04:35 | Shuichi Sekiguchi v Mohamed Safwat | 7-6,1-6,3-6 |
| ITF Japan F2 | 2018/03/13 03:15 | Daniel Nguyen v Jumpei Yamasaki | 6-1,2-6,6-1 |
| ITF Japan F2 | 2018/03/12 00:30 | Jumpei Yamasaki v Naru Shirafuji | 6-0,6-0 |
| ITF Japan F2 | 2018/03/11 00:30 | Jumpei Yamasaki v Takashi Yasugami | 6-0,6-3 |
| ITF Japan F1 | 2018/03/08 07:15 | Jumpei Yamasaki v Yuki Mochizuki | 1-6,3-6 |
| ITF Japan F1 | 2018/03/06 02:00 | Kaichi Uchida v Jumpei Yamasaki | 6-1,6-7,3-6 |
| Challenger Yokohama | 2018/02/27 04:45 | Jumpei Yamasaki v Stephane Robert | 6-3,1-6,3-6 |
| Challenger Yokohama Qual | 2018/02/26 01:00 | Jumpei Yamasaki v Masamichi Imamura | 4-6,7-6,6-4 |
| Challenger Yokohama Qual | 2018/02/25 01:00 | Maverick Banes v Jumpei Yamasaki | 6-2,1-6,4-6 |