Various information about foreigners is shared with the Immigration Bureau, municipal offices, Hello Work, and other administrative agencies, and the Immigration Bureau can easily grasp the status of part-time jobs of foreign students through the residence card.
In addition, the amount of income of foreign students will be accurately stated in units of 1 yen during the tax payment procedure performed by the employer. Of course, if the total amount of income is large relative to the hourly wage, it is suspected that the time limit has been exceeded. If an international student applies to the Immigration Bureau to renew a student visa or obtain a work visa, they are already aware of the fact that the time limit is not being met, so visa renewal or change applications are not permitted.
Therefore, even if you try to cheat, it will not pass. Observe working hours according to your status of residence.