Round: 25 Ground: Hardcourt outdoor
| ITF Japan F4 | 2016/03/28 01:00 | Kikuchi, Gengo v Watanuki, Keisuke | 2-6,7-5,6-7 |
| ITF Japan F4 | 2016/03/27 01:00 | Yusuke Takahashi v Watanuki, Keisuke | 4-6,3-6 |
| ITF Japan F3 | 2016/03/22 03:10 | Onishi, Ken v Watanuki, Keisuke | 2-6,6-2,7-5 |
| ITF Japan F3 | 2016/03/20 02:30 | Shiga, Masato v Watanuki, Keisuke | 4-6,6-2,3-6 |
| ITF Japan F3 | 2016/03/19 03:45 | Rigele Te v Watanuki, Keisuke | 2-6,1-6 |
| ITF Japan F2 | 2016/03/15 04:30 | Watanuki, Keisuke v Kibi, Yuya | 2-6,6-4,1-6 |
| ITF Japan F2 | 2016/03/13 01:00 | Aoran Wang v Watanuki, Keisuke | 0-6,4-6 |
| ITF Japan F2 | 2016/03/12 00:30 | Numajiri, Keisuke v Watanuki, Keisuke | 6-2,2-6,1-6 |
| ITF Japan F4 | 2016/03/28 01:00 | Shintaro Imai v Sasai, Masaki | 6-2,6-0 |
| ITF Japan F4 | 2016/03/27 03:00 | Shintaro Imai v Tashiro, Yuga | 6-1,6-1 |
| ITF Japan F3 | 2016/03/24 03:15 | Shintaro Imai v Gao, Xin | 6-7,3-6 |
| ITF Japan F3 | 2016/03/23 01:00 | He, Yecong v Shintaro Imai | 6-7,6-3,1-6 |
| ITF Japan F3 | 2016/03/21 02:45 | Shintaro Imai v Sidharth Rawat | 6-2,6-0 |
| ITF Japan F2 | 2016/03/18 02:45 | Shintaro Imai v Kibi, Yuya | 7-6,4-6,3-6 |
| ITF Japan F2 | 2016/03/16 01:00 | Takeuchi, Kento (1987) v Shintaro Imai | 0-6,4-6 |
| ITF Japan F2 | 2016/03/14 02:40 | Shintaro Imai v Ko Suzuki | 6-3,6-0 |