Total babies named Josai (all years): 75
| Year | Boys (count / rank / %) |
|---|---|
| 2024 | 12 / #7006 / 0.001% |
| 2023 | 12 / #7081 / 0.001% |
| 2022 | 5 / #13234 / 0.000% |
| 2021 | 6 / #11388 / 0.000% |
| 2020 | 5 / #12996 / 0.000% |
| 2019 | 10 / #7906 / 0.001% |
| 2017 | 9 / #8481 / 0.000% |
| 2013 | 6 / #11415 / 0.000% |
| 2008 | 5 / #13519 / 0.000% |
| 2005 | 5 / #12311 / 0.000% |