Well, the National Union of General Workers took up the Nova urine sampling case because there was support from Japanese union members. If there had been none, then this would not have happened. It is in the interests of Japanese workers as well, that businesses in Japan do not start such testing. The union won the case, by the way.
As for rule of law in Japan, it is just as tenuous as in Taiwan. For example, almost all 17,000 teachers on work visas in Japan are not enrolled in the mandatory government health care scheme (shakai hoken). However, in Taiwan, most teachers are enrolled or at least are informed that they can be enrolled.
Small language schools in Japan cheat foreign workers just as in Taiwan. Mom and Pop shops usually are not even aware that labour laws apply to “foreigners.” In Taiwan, you are quite fortunate that some CLA labour investigators on the west side of the island speak English. I only know of one Labour Standards Office investigator in Japan who speaks English. And he won’t even talk on the phone. He will only take faxes.
Developing trust with the Taiwanese Trade Union Federation might take years. But the issues that face Berlitz teachers in Japan and South Korea (e.g., the disrequest system) also face Berlitz teachers in Taiwan.
With a collective bargaining agreement, Berlitz can no longer change a teachers hours, where he teachers or other working conditions without having to go through the union first. This is a huge advantage for teachers.
I myself used to be sent illegally by Gloabl Village out to their Fengyuan branch from Taichung every Sunday. This is an example of a work condition violation that a union could address.