The content in this page is, by and large, taken from the JET Programme official website, but I have summarised it some and added a little bit more information on my own. If you want a comprehensive read, clicky the linky.
The Japan Exchange and Teaching (JET) Programme aims to promote grass roots internationalisation at the local level by inviting young overseas graduates to assist in international exchange and foreign language education in local governments, boards of education and elementary, junior and senior high schools throughout Japan. It seeks to foster ties between Japanese citizens (mainly youth) and JET participants at the person-to-person level.
JET Programme participants are placed in Contracting Organisations throughout Japan. Contracting Organisations consist of 47 prefectural and 17 designated city governments, individual city, town and village governments and some private schools. JET participants sign their contracts with their Contracting Organisation and as such, they are under the jurisdiction of the local authority which employs them.
There are 3 types of positions available in the JET programme – Assistant Language Teacher (ALT), Coordinator for International Relations (CIR) and Sports Exchange Advisor (SEA). More than 90% of JET participants are employed as ALTs. CIRs are required to have a functional command of the Japanese language. Applicants to the SEA position must be recommended by either the participating country’s National Olympic Committee or another government organisation.
Participants are placed with local government organisations throughout Japan in every imaginable locality, including large cities, small and medium-sized towns, and rural farming and fishing villages.
Application for participation in the JET Programme is a long and competitive process. Not only will the successful applicant receive a one year contract to live and work in Japan, but they will be comforted in the knowledge that they are backed by the Japanese Government and able to call upon an extensive support system.
Recruitment and selection of participants is conducted by Japanese embassies and consulates overseas. Individuals interested in becoming JET Programme participants should contact the Japanese Embassy in their country of citizenship.
For Singapore, the call for applications typically begin in September every year with the closing date being sometime at the end of November. But, I may be wrong, so it will do you good to call up the Japanese embassy in your country to have a check if you are interested.