I found my job by browsing the internet. There were jobs for teaching centers such as AEON, and GABA, but also jobs like the one I had for Interac, where you taught at a local school somewhere in Japan. Most jobs like this refer to you as an Assistant Language Teacher (ALT). I think searching for ALT jobs in Japan is a good way to find the companies.
For the interviews, I had to dress in a business suit and keep my appearance very nice, no ear piercings or visible tattoos. They had group information sessions where they told you about their company and what they do, then in front of the other applicants you had to teach a demo lesson for about 5 minutes. For my interac interview, they filmed me to submit the film to the Japanese board of education. Afterwards, you had an English grammar and comprehension test to make sure you knew basic grammar. This was followed by a one on one interview, and any questions you had, be sure to ask lots of questions to make sure you are interested in the job.
Working for a Japanese company can be stressful sometimes, because everything has to go be by the books. There is not much room for letting things slide. Also meetings are mandatory. Your co-workers will be professional while at work but if you get to spend time with them out of work you’ll find that many of them have very different personalities from their work life. Since I worked at a public school and my company only checked in with me once every 4 months or so. I did not have much stress from my company. I got to hang out with kids in school and my co workers were very nice to me. Sometimes it is hard because the work culture is different from the US, but after a while adjusting to the Japanese style is pretty easy. There are enkai, which is a great time to get to know your teachers. I had lots of time because of the public school schedule to explore many places in Japan.
My advice for people who are going to live in Japan, is to remember that it is not the US, things are done differently. This can sometimes be stressful. The less time you spend wishing it was done differently, the more you will enjoy your time in Japan. Also, if it isn’t illegal or too dangerous, and if you have never tried it, say “yes”. This goes for food, travel, going out with people. This will open up tons of experiences for you and you will enjoy your life in Japan much more. There’s no point to going to another country if you stay inside all the time and hang out alone. Also, do karaoke, even if you don’t sing just go. Everyone is bad, except for maybe one or two people.
UPDATE November 2013
Zach-san has a contract as a linguist in the air force and will start schooling in January.