The increased rates of payment for overtime worked in excess of 60 hours per month will also apply to SMEs

The payment rate for overtime worked in excess of 60 hours per month used to be 50% for large enterprises and 25% for small and
medium-sized enterprises, but the rate will increase from 25% to 50% or more for the latter, too, from 1 April 2023.
Please note that it will be mandatory.

Late night work
If overtime in excess of 60 hours per month is worked during the late hours (22:00 - 5:00), the following rates will apply.
Late night payment rate is 25% + overtime payment rate is 50% = 75%

Holiday work
The calculation of 60 hours of overtime per month does not include hours worked on statutory holidays, but include hours worked on other holidays.

To protect the health of workers who work more than 60 hours of overtime per month, paid leave (alternative leave) may be granted
instead of the increased payment.

However, this alternative leave scheme can only be applied, if there is a prior agreement between the company and employees, and the
employee concerned have agreed to take alternative leave.

The employment regulation and payroll calculation may need to be reviewed.

For more details on this please refer to the following URL (Japanese):
Ministry of Health, Labour and Welfare　000930914.pdf (mhlw.go.jp)