Round: 62 Ground: Hardcourt outdoor
| ITF Japan F4 | 2016/03/27 01:00 | Katsuki Nagao v Masaki Osafune | 6-1,6-2 |
| ITF Dominican Republic F2 | 2015/12/06 14:00 | Juan Carlos Aguilar v Masaki Osafune | 7-5,6-3 |
| ITF Dominican Republic F2 | 2015/12/05 13:30 | Mitchell Thomas McDaniels v Masaki Osafune | 4-6,6-7 |
| ITF Dominican Republic F1 | 2015/11/28 16:00 | Conor Berg v Masaki Osafune | 6-2,3-6,7-6 |
| ITF Turkey F41 | 2015/10/13 07:00 | Marek Semjan v Masaki Osafune | 7-6,2-6,7-6 |
| ITF Turkey F36 | 2015/10/05 07:00 | Yuanfeng Li v Masaki Osafune | 7-5,6-0 |
| ITF Turkey F36 | 2015/10/04 12:00 | Masaki Osafune v Victor-Mugurel Anagnastopol | 7-5,6-0 |
| ITF China F11 Qual | 2015/07/20 02:00 | Kittiphong Wachiramanowong v Masaki Osafune | 6-0,6-1 |
| ITF Japan F8 | 2016/06/16 02:15 | Keisuke Watanuki v Sho Katayama | 3-6,1-6 |
| ITF Japan F8 | 2016/06/15 04:30 | Shunrou Takeshima v Keisuke Watanuki | 6-7,0-6 |
| ITF Japan F7 | 2016/06/09 02:30 | Chan-Yeong Oh v Keisuke Watanuki | 6-3,6-7,6-4 |
| ITF Japan F7 | 2016/06/07 01:00 | Keisuke Watanuki v Takuto Niki | 6-4,7-6 |
| ITF Japan F6 | 2016/05/31 05:25 | Yusuke Takahashi v Keisuke Watanuki | 6-3,6-4 |
| ITF Japan F6 Qual | 2016/05/29 04:00 | Keisuke Watanuki v Sho Shimabukuro | 6-1,6-0 |
| ITF Japan F6 Qual | 2016/05/28 01:00 | Keisuke Watanuki v Shin Yoshida | 6-1,6-4 |
| ITF Japan F5 | 2016/04/06 03:40 | Keisuke Watanuki v Sho Katayama | 2-6,5-7 |