First of all, I suppose if you are an undergraduate and serious about learning Japanese, you are already in Japanese 1, or at least tried to put yourself in. I know many people who took this course, and all of them got a certain level in one year. Everyone seems to have had fun in that class too, so why not?

If you are not at the University, or perhaps you don't want that intensive learning like Japanese 1, fortunately the University has its own language teaching centre, IALS (http://www.ials.ed.ac.uk/MLC/languages/Japanese.html). There is no reason you shouldn't check out their language courses. They usually have frequent beginner classes as well as wide range of classes at different levels. Their schedules roughly follow that of university term dates so classes start in September and January. Matriculated students can get large discount on some of the courses.

This year, Japanese Society is also running own class with an experienced Japanese teacher together with some of the Society members who are keen to experience and learn how to teach Japanese. See http://eduni.japanese-society.org.uk/class1 for details.