CLAIR offers free Beginner, Intermediate, and Advanced courses. The courses starts in September and April and last six months. The courses are provided online as e-learning courses and there are unit tests at the end of each unit. Please contact your supervisor if you are interested. CLAIR also offers a Translation and Interpretation Course, although the fee must be borne by contracting organisations.
EPIC in Matsuyama and Niihama offers intensive Japanese courses during spring and summer. Ask your supervisor for more details. Large towns may also have their own language courses or private tutors. EPIC also maintains a list of organisations offering Japanese lessons and tutoring across the prefecture: http://www.epic.or.jp/kurasu/documents/English.pdf
There are 5 levels – N1 being the hardest and N5 the easiest. Tests for all levels are held every year on the first Sunday of December and July. The application deadline for the December test is in September, and the application deadline for the July test is in April. The application fee is 6000 yen and you can apply online through the JLPT website. JET now offers a small grant for those who pass Level 3: http://jetprogramme.org/en/jlpt/
If you enjoy teaching English, this is also a great time to become TEFL (Teaching English as a Foreign Language) certified. There are many online programs that you can complete in your free time to improve your teaching skills and gain valuable credentials to help you continue to teach after your time with JET. The JET Programme now offers 200 partial grants toward TEFL programs of 100 hours or more each May, so keep an eye on your email for more information when spring rolls around!