Kazuya Saito has 4 recorded races from JP.
| Date | Race | Distance | Time | Overall |
|---|---|---|---|---|
| 2025-04-13 | Schneider Electric Marathon de Paris 2025 — Schneider Electric Marathon de Paris | Marathon | 2:59:55 | 2023 |
| TCS London Marathon 2026 | Marathon | 3:00:11 | 3348 | |
| Tokyo Marathon 2026 | Marathon | 3:17:12 | 4453 |