Japanese courses on the weekends?

Hello,

Since I am living in Tokyo for 4 months already, but didn't have had much time for studying and had to realise that I won't get far, when learning on my own.
I don't need it for my job, since we speak in English, but I want to get better, since I think then life would even be more fun.

I am looking for a japanese course that is only on the weekends, since I have to work the rest of the week.
I want to start in November or if better in January, since I will leave Japan for 4 weeks in December/beginning of January.

Can someone recommend me a good language school which offers such courses. I am living in the Shibuya area by the way, so it would be good when it would be a school that is not that far away.
And although I am already know some words phrases, I am still at a beginner level.

http://www.tiuhk.com/tokyo2006/

Weekend courses would be difficult to find; it might be easier to find a school that can do a course tailored to you, or find a tutor for you. I know this school to be a good one (and in Shibuya) - see what they have available?