I'm not sure that I want to comment on this or not. I have strong feelings about Japanese family obligation and the reason these things happen.
The worry about being a failure and bringing dishonour to your family, including all your ancestors presents a unique problem. Students who don't pass their exams for entrance into university sometimes kill themselves and many people overwork themselves just to avoid family shame. I'm not sure society agrees now that family shame is so terrible. Things have relaxed a lot but it must be on people's minds for them to do these things.
When I was last in Japan and staying with a friend, her father came home around 22.00 and he was drunk. He and his colleagues had finished work some time ago, but they were obligated to spend time together "relaxing" and "socialising". Of course, this put burdens on the family life but everyone was supposed to understand because it was good for the company.
I can't finish this right now. It's too painful, but I hope the best for his family and every family out there whose loved one dies because of this.