| ITF Japan F3 | 03/25 03:00 | 28 | Duckhee Lee v Shuichi Sekiguchi | 7-5,6-3 | |
| ITF Japan F3 | 03/24 03:15 | 27 | Young Seok Kim v Shuichi Sekiguchi | 2-6,0-6 | |
| ITF Japan F3 | 03/23 01:00 | 26 | Yuya Ito v Shuichi Sekiguchi | 5-7,4-6 | |
| ITF Japan F3 | 03/22 03:30 | 25 | Ryota Tanuma v Shuichi Sekiguchi | 6-4,1-6,2-6 | |
| ITF Japan F2 | 03/18 03:20 | 27 | Shuichi Sekiguchi v Masaya Kobayashi | 3-6,2-6 | |
| ITF Japan F2 | 03/17 03:20 | 26 | Shuichi Sekiguchi v Sho Shimabukuro | 6-4,6-2 | |
| ITF Japan F2 | 03/15 03:40 | 25 | Shuichi Sekiguchi v Yuto Sakai | 6-3,6-1 | |
| ITF Japan F1 | 03/12 05:30 | 28 | Gengo Kikuchi v Shuichi Sekiguchi | 7-6,6-1 | |
| ITF Japan F1 | 03/12 01:00 | 27 | Shuichi Sekiguchi v Yuya Kibi | 6-4,6-3 | |
| ITF Japan F1 | 03/10 04:25 | 26 | Shuichi Sekiguchi v Sho Katayama | 7-5,7-6 | |
| ITF Japan F1 | 03/10 01:00 | 25 | Shuichi Sekiguchi v Masaki Sasai | 6-3,6-0 | |
| Challenger - Launceston | 02/02 04:20 | 25 | Alex Bolt v Shuichi Sekiguchi | 6-3,6-4 | |
| Challenger - Shanghai | 10/10 05:40 | 45 | Nikoloz Basilashvili v Shuichi Sekiguchi | 6-4,6-2 | |
| WTA Kuala Lumpur Qual | 09/26 02:00 | 45 | Andre Begemann v Shuichi Sekiguchi | 2-6,6-2,6-3 | |
| Challenger Kaohsiung Qual | 09/20 06:50 | 44 | Shuichi Sekiguchi v Chu-Huan Yi | 4-6,4-6 | |
| Challenger - Granby | 07/23 15:00 | 26 | Shuichi Sekiguchi v Matteo Donati | 4-6,1-6 | |
| ITF Thailand F9 | 06/27 03:00 | - | Christopher Rungkat v Shuichi Sekiguchi | 6-4,6-3 | |
| ITF Thailand F9 | 06/26 03:00 | - | Shuichi Sekiguchi v Jung-Woong Na | 6-4,6-3 | |
| ITF Thailand F9 | 06/25 03:00 | - | Shuichi Sekiguchi v Karunuday Singh | 6-0,6-2 | |
| ITF Thailand F9 | 06/24 05:00 | - | Shuichi Sekiguchi v Warit Sornbutnark | 6-4,6-3 | |
| ITF Thailand F9 | 06/22 04:15 | - | Shuichi Sekiguchi v Woo-Ram Kim | 6-2,3-6,6-1 | |
| ITF Thailand F9 | 06/20 03:00 | - | Kento Takeuchi v Shuichi Sekiguchi | 1-6,2-6 | |
| ITF Thailand F9 | 06/19 03:00 | - | Toshihide Matsui v Shuichi Sekiguchi | 4-6,4-6 | |
| ITF Thailand F9 | 06/18 05:05 | - | Christopher Rungkat v Shuichi Sekiguchi | Retired | |
| ITF Thailand F9 | 06/17 03:30 | - | Ken Onishi v Shuichi Sekiguchi | 3-6,3-6 | |
| ITF Thailand F9 | 06/16 08:10 | - | Punn Bodhidatta v Shuichi Sekiguchi | 2-6,1-6 | |
| ITF Japan F6 | 06/10 03:10 | - | Masaki Sasai v Shuichi Sekiguchi | 7-6,7-5 | |
| ITF Indonesia F3 | 04/15 03:00 | - | Shuichi Sekiguchi v Finn Tearney | 6-7,6-3,6-7 | |
| ITF Indonesia F2 | 04/12 04:00 | - | Duckhee Lee v Shuichi Sekiguchi | Retired | |
| ITF Indonesia F2 | 04/11 04:00 | - | Finn Tearney v Shuichi Sekiguchi | 0-6,1-6 |