Hello. Thai massage is great for back pain, really helps loosen things up. Look at this link for Thai massage spots in Ibaraki. The site lists traditional Thai massage salons across Japan, including Ibaraki. Thai massage uses stretching and pressure points, no oils, you wear loose clothes. I had chronic lower back pain from sitting at a desk and went to a Thai place in Tsukuba that was on that list. After three sessions my back felt way better. Sessions run sixty to ninety minutes, cost five to eight thousand yen. Most places don't need appointments, you can just walk in. Make sure they're doing traditional Thai, not just a regular massage with a Thai name.