| ITF M25 Dallas | 06/30 16:30 | 26 | Shuichi Sekiguchi v Yibing Wu | Retired | |
| ITF M25 Dallas | 06/29 16:05 | 25 | Marcus Walters v Shuichi Sekiguchi | 3-6,2-6 | |
| ITF M15 South Bend | 06/23 15:35 | 26 | Shuichi Sekiguchi v Ryan Shane | 3-6,2-6 | |
| ITF M15 South Bend | 06/22 21:20 | 25 | Shuichi Sekiguchi v Aditya Vashistha | 7-5,6-2 | |
| ITF M25 Wichita | 06/15 14:55 | 25 | Yuta Shimizu v Shuichi Sekiguchi | 3-6,6-3,6-2 | |
| ITF M15 Heraklion | 05/29 07:00 | 29 | Shuichi Sekiguchi v Simon A Ivanov | 6-3,6-1 | |
| ITF M15 Heraklion | 05/28 07:00 | 28 | Shuichi Sekiguchi v Mark Whitehouse | 6-4,6-2 | |
| ITF M15 Heraklion | 05/27 07:30 | 27 | Shuichi Sekiguchi v Stefanos Sakellaridis | 7-6,6-1 | |
| ITF M15 Heraklion | 05/26 07:00 | 26 | Shuichi Sekiguchi v Marlon Vankan | Retired | |
| ITF M15 Heraklion | 05/25 07:00 | 25 | Shuichi Sekiguchi v Gabriele Bosio | 3-6,6-4,6-0 | |
| ITF M15 Heraklion | 05/21 10:20 | 28 | Shuichi Sekiguchi v Omar Jasika | 4-6,2-6 | |
| ITF M15 Heraklion | 05/20 07:00 | 27 | Hugo Pontico v Shuichi Sekiguchi | 1-6,0-6 | |
| ITF M15 Heraklion | 05/19 06:55 | 26 | Kelsey Stevenson v Shuichi Sekiguchi | 0-6,3-6 | |
| ITF M15 Heraklion | 05/18 07:00 | 25 | Matic Dimic v Shuichi Sekiguchi | 0-6,0-6 | |
| ITF M15 Heraklion | 05/13 07:00 | 27 | Shuichi Sekiguchi v Colin Markes | 3-6,6-3,3-6 | |
| ITF M15 Heraklion | 05/12 11:05 | 26 | Shuichi Sekiguchi v Sebastian Dominko | 7-6,6-1 | |
| ITF M15 Heraklion | 05/10 08:30 | 25 | Shuichi Sekiguchi v Matthew Dellavedova | 6-4,6-2 | |
| ITF M15 Sharm El Sheikh | 04/01 08:00 | 27 | Dominik Boehler v Shuichi Sekiguchi | 4-6,6-4,7-5 | |
| ITF M15 Sharm El Sheikh | 03/31 10:15 | 26 | Karlo Cubelic v Shuichi Sekiguchi | 4-6,6-7 | |
| ITF M15 Sharm El Sheikh | 03/30 10:15 | 25 | Sahar Simon v Shuichi Sekiguchi | 6-7,1-6 | |
| ITF M25 Quinta Do Lago | 03/25 10:00 | 25 | Adria S Barrera v Shuichi Sekiguchi | 5-7,6-4,10-5 | |
| ITF M25 Loule | 03/17 13:00 | 25 | [421] Hady Habib v Shuichi Sekiguchi [466] | 6-0,6-4 | |
| ITF M25 Decatur | 08/04 18:05 | 25 | Alfredo Perez v Shuichi Sekiguchi | 6-1,7-6 | |
| Challenger Lexington | 07/26 19:25 | 25 | [249] Ulises Blanch v Shuichi Sekiguchi [350] | 6-3,6-4 | |
| Challenger Cary | 07/19 21:00 | 25 | [284] Christian Harrison v Shuichi Sekiguchi [345] | 6-4,6-4 | |
| Challenger Salinas 2 | 04/27 18:40 | 25 | [316] Shuichi Sekiguchi v Pedro Sakamoto [313] | 2-6,4-6 | |
| Challenger Salinas | 04/21 15:00 | 26 | Shuichi Sekiguchi v Nicolas Jarry | 1-6,2-6 | |
| Challenger Salinas | 04/19 16:00 | 25 | [265] Hiroki Moriya v Shuichi Sekiguchi [318] | 1-6,6-7 | |
| Challenger Orlando | 04/12 15:30 | 14 | [252] Altug Celikbilek v Shuichi Sekiguchi [307] | 4-6,6-4,7-5 | |
| Challenger Cleveland | 03/16 18:40 | 25 | Alexis Galarneau v Shuichi Sekiguchi | 6-3,6-1 |