Stadium: Court 6 Round: 54 Ground: Clay
| ITF Japan F5 | 2018/03/31 00:30 | Saito, Takashi v Onoda, Ken | 3-6,4-6 |
| ITF Greece F3 | 2018/03/10 07:30 | Moreno, Federico v Onoda, Ken | 6-3,6-4 |
| ITF Greece F2 | 2018/03/04 08:00 | Duje Ajdukovic v Onoda, Ken | 7-5,7-6 |
| ITF Greece F2 | 2018/03/03 07:30 | Onoda, Ken v Lavdas, Andreas Anastasis | 6-1,6-2 |
| Turkey F8, Singles Qualifying | 2018/02/27 07:30 | Felipe Meligeni Rodrigues Alves v Onoda, Ken | 6-4,6-2 |
| Turkey F8, Singles Qualifying | 2018/02/25 07:30 | Amar, Ran v Onoda, Ken | 3-6,5-7 |
| Turkey F8, Singles Qualifying | 2018/02/24 09:30 | Busch, Ruben v Onoda, Ken | 2-6,2-6 |
| Indonesia F8, Singles | 2017/11/28 03:30 | Onoda, Ken v Yu, Cheng-Yu | 1-6,2-6 |
| ITF Japan F4 | 2018/03/25 01:00 | Moritani, Soichiro v Sasai, Masaki | 6-4,6-3 |
| ITF Japan F4 | 2018/03/24 00:00 | Takuya Kumasaka v Sasai, Masaki | 3-6,6-4,3-6 |
| ITF Japan F3 | 2018/03/18 01:30 | Issei Okamura v Sasai, Masaki | 6-3,6-1 |
| ITF Japan F3 | 2018/03/17 04:00 | Tagata, Ryohei v Sasai, Masaki | 5-7,6-3,2-6 |
| ITF Japan F2 | 2018/03/12 00:30 | Murray, Jack v Sasai, Masaki | 6-4,6-3 |
| ITF Japan F1 | 2018/03/07 01:00 | Sasai, Masaki v Yuta Shimizu | 5-7,6-7 |
| ITF Japan F1 | 2018/03/06 01:00 | Sho Shimabukuro v Sasai, Masaki | 6-7,3-6 |
| ITF Japan F1 | 2018/03/04 03:00 | Numajiri, Keisuke v Sasai, Masaki | 1-6,6-3,0-6 |