| ITF Japan F5 | 2015/06/04 02:00 | Томас Фанкут v Keisuke Watanuki | 7-5,7-6 |
| ITF Japan F5 | 2015/06/03 06:30 | Ротаро Мацумура v Keisuke Watanuki | 6-2,4-6,0-6 |
| ITF Greece F9 | 2015/04/29 10:05 | David Simunek v Keisuke Watanuki | 6-4,6-2 |
| ITF Greece F5 | 2015/04/23 07:00 | Том Кочевар-Десман v Keisuke Watanuki | 6-3,6-2 |
| ITF Greece F5 | 2015/04/21 10:40 | Charalampos Kapogiannis v Keisuke Watanuki | 6-3,1-6,5-7 |
| ITF Greece F4 | 2015/04/12 11:00 | Keisuke Watanuki v Стефан Фрлянич | 6-4,2-6,5-7 |
| ITF Japan F3 | 2015/03/21 02:30 | Исей Окамура v Keisuke Watanuki | 6-2,6-3 |
| ITF Japan F2 | 2015/03/14 00:30 | Soichiro Moritani v Keisuke Watanuki | 6-4,6-2 |
| ITF Japan F5 | 2015/06/06 03:00 | Такаши Саито v Hiromasa Oku | 6-3,6-1 |
| ITF Japan F5 | 2015/06/05 02:35 | Hiromasa Oku v Макото Очи | 2-6,6-2,6-4 |
| ITF Japan F5 | 2015/06/04 01:00 | Hiromasa Oku v Yuichi Ito | 6-0,6-1 |
| ITF Japan F5 | 2015/06/02 03:15 | Hiromasa Oku v Koichi Sano | 6-4,3-6,6-2 |
| ITF Guam F1 | 2015/05/29 00:00 | Hiromasa Oku v Takao Suzuki | 6-4,6-7,5-7 |
| ITF Guam F1 | 2015/05/27 00:00 | Hiromasa Oku v Masayoshi Ono | 6-0,6-2 |
| ITF Guam F1 | 2015/05/26 00:00 | Hiromasa Oku v Masaki Sasai | 6-1,6-1 |
| ITF Thailand F9 | 2015/04/28 03:00 | Yuichi Ito v Hiromasa Oku | 6-4,2-6,4-6 |