JB changes its layout a LOT (emphasize the 'a lot' part)! I visited around two months ago or so, and it was something like heat-resistance on the main floor, with non-heat and clip-ons on the second floor. But I just visited it today, and now it's heat-risistance with clip-ons/tie-ons/extensions on the main floor, with non-heat resistant and for sale ones on the second floor. But, I think their services are really good ^ ^. I just visited it an hour ago (around 5 to 6-ish), and the store had a large group of customers in it. They were all purchasing stuff, so I didn't get a chance to talk to the saleswoman (there was only one) until they were done. She was really friendly, offering to teach me how to wear a wigcap, and all that. When I was purchasing the items, she gave me all sorts of advice on taking care of wigs, and even shared a couple of personal experiences. It just made me feel...good...like, even though the only real relationship we had was customer-clerk, it felt like we were buddies xD
As for Cosmo...I don't really like it >< I went to the one in 西門町, and I do not enjoy my experiences there. The first time I went there a year ago, the store was empty except for one clerk. She didn't say anything to us at all, until one of my friends touched a wig and she just ran over and said 'please do not touch the wigs'. My friend asked 'how would we know the quality of the wigs if we don't touch it?' and she just replied 'our wigs are all in best quality, etc'. But when we left, this group of people who seemed to have been there a couple of times went in, and they were playing around with the wigs but she didn't seem to care. The second time I went there half a year ago, only one customer was in it, and a clerk was helping her style a wig. This clerk was a bit friendler than the previous, because she said Hi. But she pretty much ignored us for the whole time, even when she was done stlying.
I hardly ever go to actual 'shops' though..most of the time I buy them on Ruten =P