Working in Japan for several years I feel qualified enough to answer.
Too little input, but let's try to give a general answer.
First of all, as long as you are ready to change yourself and adapt, Japan is no different to other countries in this respect. You definitely must learn the language, adapt to some cultural differences and be ready to get upset by few of them.
Next but not less important is to study about the company you are going to work for. If this is a foreign company with office in Japan, this is the best case for a foreigner beginner, as you won't be exposed to the full spectrum of Japanese business culture. Plus, most co-workers in such companies are quite loyal and used to foreigners, so you will feel at home.
If a company is hardcore Japanese corporation, the things get harder, but only in terms of adaptation. Co-workers tend to be less forgiving and less used to foreigners, therefore you may have harder time to adapt to all the difference.
I doubt if Japan's high suicide rate is related to working stress. Japanese companies have no more and no less stress than average western companies, so this is really not much different.
So, my message is: working in Japan is not much more stressful and not much more different than, say, working in US or Europe. There are differences in length of working day, but it just needs some adaptation.
However, when it comes to life in Japan most foreigners are unprepared.
It is hard to summarise the whole thing into one answer, but I really-really recommend you to study about general living conditions in a region you are going to stay. Depending on a region it will be different.
Housing is different, lifestyle is different, transportation is different, food is different. One may set up the expat's lifestyle, removed from the society, but it is expensive and hardly worth the effort. Integrating and living Japanese life with all its fun and sad sides is much more fun.
The answer is very generalised so please make concrete questions so that we can answer directly.