Koji Kumagai
- Date of birth/Age: Oct 23, 1975 (48)
- Place of birth: ---, Aomori
- Citizenship:
Japan
- Avg. term as coach : 3.00 Years
Former player:
Most games for :
Kashima Antlers
Retired :
-
History
This is an overview of the career of a manager.
| wappen | Club & role | Appointed | In charge until | from / until | Days in charge | Matches | W | D | L | Players used | ø-Goals | PPM | Games / PPG | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
 | Vanr. Hachinohe Sporting Director | 22/23 (Feb 1, 2023) | 23/24 (Mar 3, 2024) | 22/23 (Feb 1, 2023) / 23/24 (Mar 3, 2024) | 396 Days | - | - | - | - | - | 0.00 : 0.00 | 0.00 | - | |
 | Albirex U18 Manager | 21/22 (Feb 1, 2022) | 22/23 (Jan 31, 2023) | 21/22 (Feb 1, 2022) / 22/23 (Jan 31, 2023) | 364 Days | - | - | - | - | - | 0.00 : 0.00 | 0.00 | - | |
 | Kashima Antlers Assistant Manager | 19/20 (Jan 4, 2020) | 21/22 (Jul 27, 2021) | 19/20 (Jan 4, 2020) / 21/22 (Jul 27, 2021) | 570 Days | - | - | - | - | - | 0.00 : 0.00 | 0.00 | - | |
| Assistant Manager of: Antônio Carlos Zago (48 Games), Naoki Soma (21 Games), Carlos Pacheco (1 Game) | ||||||||||||||
| Kashima Antlers Scout | 18/19 (Feb 1, 2019) | 19/20 (Jan 3, 2020) | 18/19 (Feb 1, 2019) / 19/20 (Jan 3, 2020) | 336 Days | - | - | - | - | - | 0.00 : 0.00 | 0.00 | - | |
 | Antlers U18 Manager | 13/14 (Feb 1, 2014) | 18/19 (Jan 31, 2019) | 13/14 (Feb 1, 2014) / 18/19 (Jan 31, 2019) | 1825 Days | - | - | - | - | - | 0.00 : 0.00 | 0.00 | - | |
| Antlers U18 Assistant Manager | 10/11 (Feb 1, 2011) | 13/14 (Jan 31, 2014) | 10/11 (Feb 1, 2011) / 13/14 (Jan 31, 2014) | 1095 Days | - | - | - | - | - | 0.00 : 0.00 | 0.00 | - | |
| Kashima Antlers Scout | 05/06 (Feb 1, 2006) | 10/11 (Jan 31, 2011) | 05/06 (Feb 1, 2006) / 10/11 (Jan 31, 2011) | 1825 Days | - | - | - | - | - | 0.00 : 0.00 | 0.00 | - | |