Stadium: Court 4 Round: 46 Ground: Hardcourt outdoor
| Challenger Kyoto Qual | 2017/02/18 05:25 | Yunseong Chung v Niki, Takuto | 2-6,6-7 |
| ITF Japan F2 | 2016/03/15 02:25 | Niki, Takuto v Yunseong Chung | 3-6,6-3,3-6 |
| Yokohama, Japan, Qualifying | 2018/02/24 05:05 | Shiga, Masato v Yunseong Chung | 0-6,5-7 |
| Spain F4, Singles Qualifying | 2018/02/08 11:00 | Ivan Gakhov v Yunseong Chung | 6-4,6-4 |
| ITF Spain F3 | 2018/01/30 13:40 | Gimeno-Traver, Daniel v Yunseong Chung | 6-4,6-1 |
| ITF Spain F2 | 2018/01/27 10:00 | Yunseong Chung v Munoz-De la Nava, Daniel | 3-6,4-6 |
| ITF Spain F2 | 2018/01/26 13:00 | Monteiro, Joao v Yunseong Chung | 7-6,5-7,3-6 |
| ITF Spain F2 | 2018/01/25 09:00 | Yunseong Chung v Tyurnev, Evgeny | 6-4,2-6,6-3 |
| ITF Spain F2 | 2018/01/23 10:35 | Yunseong Chung v Mertens, Nico | 6-4,6-3 |
| ITF Spain F1 | 2018/01/20 11:50 | Munoz-De la Nava, Daniel v Yunseong Chung | 6-4,6-3 |
| Yokohama, Japan, Qualifying | 2018/02/24 07:05 | Niki, Takuto v Balaji, N. Sriram | 3-6,7-6,7-5 |
| Challenger Kyoto Qual | 2018/02/19 03:45 | Blake Ellis v Niki, Takuto | 6-3,6-4 |
| Challenger Kyoto Qual | 2018/02/18 06:05 | Osafune, Masaki v Niki, Takuto | 3-6,2-6 |
| Challenger Kyoto Qual | 2018/02/17 07:50 | Itsusaki, Kaito v Niki, Takuto | 4-6,0-6 |
| Challenger - Burnie - Qualifications | 2018/01/27 06:00 | Niki, Takuto v Prashanth, N. Vijay Sundar | 4-6,3-6 |
| Challenger - Burnie - Qualifications | 2018/01/27 02:25 | Niki, Takuto v Bosancic, Thomas | 6-3,6-2 |
| ITF Hong Kong F6 | 2018/01/04 02:00 | Viola, Matteo v Niki, Takuto | 6-1,6-3 |
| ITF Hong Kong F6 | 2018/01/03 02:00 | Zhao, Lingxi v Niki, Takuto | 1-6,1-6 |