Pros
Many excellent people, friendly environment, challenging work, diverse technologies. People who stay are either hard workers (good) or incompetent (bad). Overachievers, either by technical skills and/or relationships with customers will be recognized by peers and by being given more responsibility. Job for life if you have a heartbeat and don't do something completely stupid. Denso really works to protect employment. New technology everywhere -- basically every product has significant investments in next gens, thanks mostly to Mother Toyota.
Cons
The company has struggled to reward overachievers financially. Good people stay while great people leave (for more money, title, career path). There is a bamboo ceiling which some will try to break through, but in truth, most Sr Managers or Directors just live with. The Japanese tolerate submissive American managers because the latter don't challenge for the key executive positions held temporarily by Japanese expats. The resulting managerial complacency & incompetency is really sad to see at such a good company. Working with Japanese customers or product teams in Japan will kill your work-life balance simply because of the time zone difference and the daily coordination with Japan required to do a good job. The company tolerates weak performers. Pay is at or below market but that is for job security in down-times. IT is really behind the times because the Japanese mothership is slow to invest in new technologies for workers White collar productivity is really low for a company with such state of the art manufacturing capabilities.