| Date | IP Address |
| 2021-07-15 | 13.226.186.103 (ClassC) |
| 2021-07-15 | 13.226.186.75 (ClassC) |
| 2024-02-26 | 99.84.66.111 (ClassC) |
| 2025-08-27 | 99.84.66.97 (ClassC) |
| 2025-09-23 | 99.84.66.46 (ClassC) |
| 2025-11-02 | 3.169.173.95 (ClassC) |
| Date | Domain | IP |
| digital.dev.kumon.co.jp | 2024-12-31 | 99.84.66.29 |
| instructor.digital.dev.kumon.co.jp | 2024-02-26 | 99.84.66.111 |
| content.digital.dev.kumon.co.jp | 2024-02-17 | 13.224.14.18 |