Getting a job in Japan is hard. The visa issue makes it fundamentally difficult for foreigners, but so do misconceptions about the way to go about getting a job. The first thing to realize is that gengo nōryoku (言語能力, language skills) alone are unlikely to land you the position you want: The whole country is full of folks who speak Japanese at least as well as you do. Having other marketable skills is critical — but so is knowing Japanese job-hunting culture.
One of the most interesting aspects of Japanese job-hunting is jiko PR (自己PR, literally, "self-public relations"), one of the few times when Japanese — stereotypically known for their circumspection and humility — are forced to boldly brag and loudly proclaim about their abilities and accomplishments. Getting a job means mastering jiko PR, and mastering jiko PR means understanding its origins.
My own theory, which I've substantiated only with my own experience, is that the jiko PR tradition is strongly intertwined with the ōendan (応援団, cheerleading team) and bukatsu (部活, school club/sports) culture in Japanese schools.