| ITF Japan F5 | 04/01 00:30 | 54 | Yu Hsiang Chiu v Masaki Osafune | 6-2,6-2 | |
| ITF Japan F5 | 03/31 00:30 | 54 | Masaki Osafune v Shunsuke Wakita | 6-7,6-3,6-0 | |
| ITF Japan F4 | 03/25 05:00 | 62 | Masaki Osafune v Yu Hsiang Chiu | 2-6,4-6 | |
| ITF Japan F2 | 03/12 00:30 | 44 | Soichiro Moritani v Masaki Osafune | 7-6,6-0 | |
| ITF Japan F1 | 03/06 01:00 | 62 | Naru Shirafuji v Masaki Osafune | 6-0,6-3 | |
| ITF Japan F1 | 03/03 04:30 | 62 | Cheong Hwi Kim v Masaki Osafune | 1-6,1-6 | |
| Challenger Kyoto Qual | 02/18 06:05 | 46 | Masaki Osafune v Takuto Niki | 3-6,2-6 | |
| Challenger Toyota Qual | 11/11 02:15 | 45 | Yuto Sakai v Masaki Osafune | 7-6,1-6,6-1 | |
| ITF Guam F1 | 06/22 03:25 | 26 | Masaki Osafune v Yuichi Ito | 2-6,4-6 | |
| ITF Guam F1 | 06/20 06:00 | 25 | Masaki Osafune v Steven Goh | 6-3,6-4 | |
| ITF Japan F8 | 06/11 00:00 | 62 | Masaki Osafune v Daisuke Sumizawa | Retired | |
| ITF Japan F7 | 06/06 04:05 | 25 | Renta Tokuda v Masaki Osafune | 6-1,3-6,6-1 | |
| ITF Japan F7 | 06/04 01:00 | 54 | Masaki Osafune v Shoma Kato | 6-3,6-3 | |
| ITF Japan F6 Qual | 05/29 03:40 | 54 | Yuki Matsuo v Masaki Osafune | 7-6,6-2 | |
| ITF China F7 | 05/17 03:40 | 26 | Dayne Kelly v Masaki Osafune | 6-1,6-1 | |
| ITF China F7 | 05/16 05:30 | 25 | Jui-Chen Hung v Masaki Osafune | 2-6,6-1,2-6 | |
| ITF China F7 Qual | 05/15 03:55 | 62 | Chukang Wang v Masaki Osafune | 7-5,4-6,1-6 | |
| ITF China F7 Qual | 05/14 02:55 | 62 | Masaki Osafune v Calum Puttergill | 7-5,6-1 | |
| ITF China F7 Qual | 05/13 06:30 | 62 | Louis Clark v Masaki Osafune | 1-6,5-7 | |
| ITF China F6 | 05/09 03:10 | 25 | Masaki Osafune v Yan Bai | 2-6,2-6 | |
| ITF China F6 Qual | 05/08 03:25 | 62 | Masaki Osafune v Kazuma Kawachi | 6-2,6-4 | |
| ITF China F6 Qual | 05/07 01:30 | 62 | Masaki Osafune v Liran Chen | 6-3,6-3 | |
| ITF China F6 Qual | 05/06 04:30 | 62 | Xiao Gong v Masaki Osafune | 6-0,4-6,5-7 | |
| ITF Japan F4 | 03/30 03:15 | 26 | Ryota Tanuma v Masaki Osafune | 7-5,3-6,6-3 | |
| ITF Japan F4 | 03/29 05:10 | 25 | Masaki Osafune v Arata Onozawa | Retired | |
| ITF Japan F4 | 03/28 02:00 | 62 | Masaki Osafune v Rio Noguchi | 1-6,7-6,6-3 | |
| ITF Japan F4 | 03/25 02:00 | 62 | Hiromasa Oku v Masaki Osafune | 1-6,0-6 | |
| ITF Japan F3 | 03/18 03:00 | 62 | Masaya Kobayashi v Masaki Osafune | 7-6,6-7,6-4 | |
| ITF Japan F2 | 03/12 02:00 | 44 | Kittiphong Wachiramanowong v Masaki Osafune | 6-3,6-4 | |
| ITF Japan F2 | 03/11 03:00 | 44 | Masaki Osafune v Artem Vu | 6-2,6-1 |