I didn't work directly under Japanese management, only indirectly or as a b2b partner. I was never told directly to work longer hours as a result, there was some pressure from non japanese intermediaries.

There are also some unspoken expectations and etiquette rules that should be observed, which might create an environment heavier on work side.

Most of my understanding of the work culture comes from people I talked to who worked directly under Japanese management, and it can get tough, I never heard of someone directly being confronted, but heard about more subtle ways to ensure performance and obedience.

Its only my guess living and working in Japan this would be on completely another level.