In order to succeed in this cut-throat competitive global market, one needs to have sound communication skills to make one stand out in the crowd. In order to be competitive in business market, one should have fluency in English language to state one's ideas / views clearly. However, it is very important that one gets the right guidance to learn English language effectively and efficiently. Buying essays online is helpful.

One way could be to have a look at the JET Program - details here. This is an exchange program where participants are placed in a school or other organisation for a year, usually as a teaching assistant. It can be a good way in, so you may like to look at the site and maybe contact the Japanese embassy in your country for further details.
For regular TEFL jobs, especially with adults, you should look at the EFL job sites - there are usually jobs being advertised, such as here for example. Many Japanese institutions are less concerned about TEFL qualifications than some other countries, although it is much easier to find work if you have a degree or other higher level qualification. However, if you don't have a TEFL certificate it is a very good idea to get one - it will improve your chances of getting a job in a good school, get you in touch with a bigger job market and, most of all, make you a better teacher.