After a month of waiting, I finally assembled a kotatsu today. A kotatsu, these days, is usually a table with a small heater built into the top of a frame, covered with a blanket and then topped with a tabletop. A couple of pictures might help you sort that all out:
(NB: my legs are supposed to be under the blanket)
It's a very elegant way of saving energy while increasing the pleasure of warmth in cold weather. I'm excited, not only about the kotatsu, but also about getting rid of the stupid desk I had before—it seemed very out of place in my Japanese-style room. Now, for perhaps the first time in my life, I really love my room. It's comfortable, and it just seems to fit somehow.
There's no real need now for the heater, though I've been using it today just to try it out. But I don't think even global warming can completely destroy the notoriously cold winters here, and I imagine I'll have a chance to use it as more than just a curiosity piece.
I was able to get a particularly good deal on this setup, something that just adds to my enjoyment. A reasonable kotatsu—not cheap but presentable as a table in winter and summer—usually costs 15,000-20,000, an amount I just can't afford at the moment. I frequent the thrift stores around here—and Adachi appears to really be one of the best places in Tokyo for them—but I wasn't able to find one that fit my plans, a rectangular affair that would still fit well in my room. I'd found many square ones, and a couple rectangular ones that just seemed too big, but in the end I managed to find a kotatsu table, a frame with space for the heater and the table-top, for 1000 yen. I think it was new, though I scratched it a bit carrying it home (an hour long ordeal). It fits perfectly in my room. I did some measurements and found I could easily put in a heater, and today I headed over to Akihabara (the electronics district; I could have easily gone somewhere here in Adachi, but decided to head there since I hadn't been for a while), picked one up for 4000 yen, and now I'm set. I got exactly what I wanted for a third the cost of a new one, and for a price comparable to the cheaper, older setups I had seen at the thrift stores. Very happy.