The problem is cultural. It's not something you fix by stupid regulations. The fact that people feel obligated to stay long hours because their boss is in the office, and the whole concept of "we are all in this together so we should all suffer together" is a key driver. It's not unique to Japan at all by the way, Korea and some other Asian countries have the same problem, and this is rooted in a long tradition of Confucianism. Japan is the not the West.