Hey Olivier,

Welcome to Chalkboard! That's great you're going to be heading to Japan - you should chat to Emma who's taught there to see if she's got any tips/advice for you: http://www.tefl-chalkboard.com/emmafoers

You might also want to check out the discussions going on in the Japan group: http://www.tefl-chalkboard.com/groups/8-Japan

Good luck with it all and if you have any questions feel free to get in touch and I'll do my best to help!