1 . Education
BA or BS from an accredited university, or enough teaching experience. Although some teaching experience is preferred, it is not required because all teachers will undergo some training before beginning any position.
2 . Japanese Language
Basic Japanese conversation level or higher is desired. If you don't know much or any Japanese, you will need to study enough to reach a basic conversation level, though being skilled in Japanese is not demanded. Although you should be using as much English as you can at school, there are times when the Japanese teachers and students, in particular, will not understand you. Supporting their English interaction with a little Japanese makes the relationships among yourself, students, and teachers much smoother and better. Having a little bit of Japanese skill will make working and living in Japan much easier and more enjoyable. Even a little effort in trying to understand Japanese often goes a long way with your students and coworkers, so you don’t have to stress over becoming fluent.
3 . Financial
You will need enough money to cover the costs of moving to and settling in Japan. There are the obvious costs of plane tickets, food, accommodations, and so on, but after first arriving, you will most likely not see a full paycheck until after your first two full months of work. In Japan, workers are paid once a month, usually towards the end of the following month. This means that if you arrive in Japan in the middle of March, but you don’t start working until April, you will not see any money for April until the end of May. Therefore you should plan on having enough money to hold you over for about two months. The Japanese government recommends you have about 4,000 US dollars to cover the initial costs of moving.
4 . Desired qualities
Moving to a foreign country to work is not something to be taken lightly. It is a major decision, and one should carefully consider whether working in Japan is the right thing. It takes a certain amount of independence and courage to move to a foreign country by yourself. Can you handle being away from your friends and family back home for at least a year? If you are not proficient in Japanese, living and getting by in Japan is certainly possible, but is often filled with frustration, difficulties, and embarrassment. So if you are not skilled in Japanese, can you handle learning a new culture and lifestyle without being able to communicate as freely as in your home country? Can you also handle being in a workplace where most of the people (i.e. students and teachers) are not using English? It could become a little isolating and lonely if you do not have the desire to try learning something new.
All aspects of living and working in Japan should be thoroughly considered before making a final decision. With that said, you should also not necessarily let these considerations scare you. Part of the excitement and enrichment in life is to try new things. Getting lost or confused is not necessarily something that should scare you away. Moving to a new country where you don’t know the native language is also a great opportunity to challenge yourself, become a stronger individual, and gain interesting experiences.