Shuichi Koyama has 7 recorded races from JP.
| Date | Race | Distance | Time | Overall |
|---|---|---|---|---|
| 2025-04-13 | Schneider Electric Marathon de Paris 2025 — Schneider Electric Marathon de Paris | Marathon | 2:44:06 | 348 |
| 2024-04-07 | Schneider Electric Marathon de Paris 2024 — Marathon de Paris 2024 | Marathon | 2:50:28 | 795 |
| TCS London Marathon 2026 | Marathon | 2:38:11 | 554 | |
| BMW Berlin Marathon 2025 | Marathon | 2:59:07 | 2114 | |
| TCS London Marathon 2025 | Marathon | 2:43:13 | 858 |