I finally found some information about tap dance classes in Tsukuba!
There is a group called “Planet-N” that meets on the first through fourth Mondays of the month at a studio called “Gallery Yuu” (see map links below) in the Sakura area of Tsukuba. The classes on the first, third, and fourth Mondays are held by a teacher who comes in from Tokyo. The class on the second Monday is for individual practice. There is no class on the fifth Monday. Classes start at 7pm and officially go until 8:30pm, but apparently they tend to go past 9pm on a regular basis. They accept newcomers at anytime.
The lessons cost 9500 yen per month. It is possible to take a trial lesson for 2500 yen (only available once). You can also observe the class once for free.
Directions: Go to Sakura Technopark. At the first intersection past Kawachi and Yuuhodo Bookstore (the intersection with the eyeglasses store on the left), turn left. At the fifth intersection, turn right. Go up a little hill and you will see the studio on your left. (Look for the sign that says ギャラリー遊.) It is in a house that is set back from the road. Parking is available on the right.
This information is from the Tsukuba Piazza bulletin board. If you are interested in finding out more information about the classes, please respond to the person who posted the original message (or contact TsukuBlog and we will put you in touch with the teacher).
I went to observe the class last night and it looks fun. The teacher is really energetic and enthusiastic and he is happy to accept absolute beginners. If you are looking for a way to get some exercise and learn a new skill, this might be an activity to consider.