ITF China F13 07/18 07:05 25 Jui-Chen Hung v Issei Okamura 6-4,6-2
ITF Guam F1 06/21 02:30 25 Takao Suzuki v Issei Okamura 7-5,6-4
ITF Japan F8 06/13 01:30 25 Shunrou Takeshima v Issei Okamura 6-3,7-5
ITF Japan F7 06/07 03:35 26 Issei Okamura v Haru Inoue 6-7,2-6
ITF Japan F7 06/06 02:40 25 Masato Shiga v Issei Okamura Retired
ITF Japan F6 05/30 03:55 25 Kento Takeuchi v Issei Okamura 7-6,6-3
ITF Singapore F1 05/25 02:00 25 Issei Okamura v Kazuki Nishiwaki 6-7,1-6
ITF China F7 05/16 07:00 25 Issei Okamura v Yusuke Takahashi 7-5,2-6,4-6
ITF China F6 05/10 06:05 26 Dayne Kelly v Issei Okamura 6-4,6-3
ITF China F6 05/08 05:30 25 Ruikai Wang v Issei Okamura 3-6,1-6
Challenger Anning Qual 04/22 03:35 45 Issei Okamura v Denys Molchanov 6-4,3-6,4-6
Challenger Taipei Qual 04/17 04:35 54 Ruan Roelofse v Issei Okamura 6-4,6-2
Challenger Taipei Qual 04/16 05:55 46 Shao-Fan Liu v Issei Okamura 6-7,6-4,3-6
ITF Japan F5 04/04 00:30 25 Issei Okamura v Takao Suzuki 6-7,3-6
ITF Japan F4 03/28 03:00 25 Kaito Uesugi v Issei Okamura 6-3,6-3
ITF Japan F3 03/22 06:00 26 Shane Vinsant v Issei Okamura 6-2,6-3
ITF Japan F3 03/20 02:35 25 Daisuke Sumizawa v Issei Okamura 2-6,2-6
ITF Japan F2 03/13 04:00 25 Issei Okamura v Nam Hoang Ly 2-6,2-6
ITF Japan F1 03/07 02:30 25 Issei Okamura v Yuki Mochizuki 2-6,4-6
ITF China F3 03/01 07:35 26 Issei Okamura v Marco Bortolotti 3-6,5-7
ITF China F3 02/28 02:00 25 Issei Okamura v Chuhan Wang Retired
ITF China F2 02/23 03:00 26 Issei Okamura v Jose Statham 1-6,3-6
ITF China F2 02/21 02:00 25 Caio Silva v Issei Okamura 1-6,0-6
ITF China F1 02/15 02:00 25 Danilo Petrovic v Issei Okamura 6-3,6-2
Challenger Launceston Qual 02/04 01:25 46 Issei Okamura v Zach Itzstein 6-3,4-6,6-7
Challenger Burnie kvalifikace 01/28 04:10 46 Dane Propoggia v Issei Okamura 6-4,6-2
Challenger Burnie kvalifikace 01/27 23:00 45 Jeremy Beale v Issei Okamura 6-1,3-6,2-6
ITF Thailand F5 12/20 03:00 25 Wishaya Trong'kul v Issei Okamura 6-2,7-6
ITF Thailand F4 12/13 03:00 25 Kittiphong Wach'ong v Issei Okamura 6-0,6-0
ITF Indonesia F5 12/07 07:10 25 David Agung Susanto v Issei Okamura 6-1,6-4