If you are like the majority of JET returnees, you went to Japan shortly after graduation, with little or no professional work experience. If this is true for you, you must show employers the real value of the JET experience, both the obvious skills such as adaptability and independence and the less obvious skills such as organizational, interpersonal and administrative skills. I'm sure that both you and your friends and family have noticed changes in you over the past few years that can be attributed to your time in Japan. All this said, job hunting is still a difficult and sometimes scary process. Don't let this daunting task dampen your enthusiasm.
Positive energy is one of the greatest barrier breakers in finding a job.
At your age, you don't have enough experience to warrant more than 1 or 2 pages. For example, be selective about your pre-graduate work experience if you are running out of space. Japanese employers are already quite familiar with the JET program, so you may not need to give great detail about the program or a lot of information about your teaching experience. These things give some personality to your r sum and may make an employer more interested in meeting you. Keep in mind all the things that are helpful in all interviews.