| ITF M15 Yanagawa | 10/29 00:30 | 54 | Ko Nagashima v Yuhei Kono | 3-6,1-6 | |
| ITF M15 Tanagura | 10/22 02:15 | 25 | Seungmin Park v Ko Nagashima | 6-2,6-3 | |
| UTR Pro Kawaguchi | 08/17 04:18 | - | Taketo Takamisawa v Ko Nagashima | 6-4,6-3 | |
| UTR Pro Kawaguchi | 08/15 10:30 | - | Ko Nagashima v Koki Takada | 6-3,6-0 | |
| UTR Pro Kawaguchi | 08/14 23:30 | - | Ko Nagashima v Sora Fukuda | 2-6,2-6 | |
| UTR Pro Kawaguchi | 08/14 02:48 | - | Yuta Kikuchi v Ko Nagashima | 6-0,6-2 | |
| UTR Pro Kawaguchi | 08/13 01:00 | - | Yuta Tomida v Ko Nagashima | 6-4,6-1 | |
| ITF M15 Karuizawa | 05/30 07:05 | 25 | Kazuma Kawachi v Ko Nagashima | 6-2,6-3 |