Round: 62 Ground: Hardcourt outdoor
| ITF - Japan F3 | 2017/03/18 03:00 | Yuga Tashiro v Hiromasa Oku | 6-3,6-2 |
| ITF Korea F8 | 2016/09/06 02:55 | Young Seok Kim v Hiromasa Oku | 6-0,6-2 |
| ITF Korea F7 | 2016/08/30 06:45 | Hiromasa Oku v Jeamoon Lee | 3-6,6-7 |
| ITF Korea F8 | 2016/08/22 02:30 | Jung-Woong Na v Hiromasa Oku | 4-6,6-1,6-0 |
| ITF - Vietnam F8 | 2016/08/01 02:00 | Hiromasa Oku v Sora Fukuda | 2-6,3-6 |
| ITF - Vietnam F8 | 2016/07/30 05:30 | Hiromasa Oku v Ansu Bhuyan | 5-7,6-4,7-5 |
| ITF - Japan F8 | 2016/06/15 04:30 | Kazuki Nishiwaki v Hiromasa Oku | 2-6,6-3,6-4 |
| ITF - Japan F7 | 2016/06/07 03:40 | Hiromasa Oku v Sho Katayama | 1-6,2-6 |
| ITF - Japan F3 | 2017/03/18 03:00 | Masaya Kobayashi v Masaki Osafune | 7-6,6-7,6-4 |
| ITF - Japan F2 | 2017/03/12 02:00 | Kittiphong Wachiramanowong v Masaki Osafune | 6-3,6-4 |
| ITF - Japan F2 | 2017/03/11 03:00 | Masaki Osafune v Artem Vu | 6-2,6-1 |
| ITF - Japan F1 | 2017/03/05 01:00 | Masaki Osafune v Keisuke Watanuki | 6-7,6-0,2-6 |
| ITF - Japan F4 | 2016/03/27 01:00 | Katsuki Nagao v Masaki Osafune | 6-1,6-2 |
| ITF - Dominikanische Republik F2 | 2015/12/06 14:00 | Juan Carlos Aguilar v Masaki Osafune | 7-5,6-3 |
| ITF - Dominikanische Republik F2 | 2015/12/05 13:30 | Mitchell Thomas McDaniels v Masaki Osafune | 4-6,6-7 |
| ITF - Dominikanische Republik F1 | 2015/11/28 16:00 | Conor Berg v Masaki Osafune | 6-2,3-6,7-6 |