BBC Learning English has lots of useful free material for learning English, including weekly lessons, recipes, a “words in the news” section and quizzes.
Lang-8 is a language exchange site. You can write a diary in English and have it corrected by native speakers, and then help others who are learning Japanese by correcting their diaries.
This page is an archive of the teaching material for an informal English conversation class that I have started for the students in my lab at Tohoku University, Sendai, Japan. It’s mainly intended for them, and will concentrate on the areas that present most difficulty for people whose first language is Japanese, but if anyone else finds the material useful, they are welcome to use it.