Don't expect a fast paced environment like in your typical Internet company. Projects take ages to be completed due to very vertical management, bad organization (0 standard & methodology, no common tool nor processes, no will to collaborate), communications issues (some japanese speakers only, some english speakers only...), low skills at strategic or very technical positions and huge turn over.
Due to the low quality standards, projects are not really compelling.
Employees don't have much interest in projects progress and innovations. They just enjoy their benefits (job security, free lunch...) and wait for the retirement.
On the other hand, its one of the rare places in Japan where you can work without speaking Japanese. The free lunch is delicious and office is confortable.
If you are looking for a secured job with no stress and a good work life balance, this is probably the best place to work.
If you are young, dynamic, motivated, if you look for challenges and work excitement... Apply somewhere else.