There are actually 7 or more Dorama stores in Shimokita, all with overlapping purposes. Video and video game rental and sales, used and new CD's/DVD's, used book sales,... What I discovered is that there is a really good used English CD selection, and prices are excellent. The best time to shop is when they are running their '200 yen off every used CD' deal. Some of the used CD's I chose were only 400 or 500 yen to begin with. There was also a rack that was 50% the price marked, 70% off if you choose more than 3. From that rack, I got four recent (within the past couple of years) CD's for a total of 1200 yen.
Dorama locations are all over, but most are on the south side of the station.