I just found out that also the cult Akiba shop M's Pop Life Department got a great selection of sexy Christmas costumes. (old "sexy xmas" post here). M's is my favourite audlt shop in the world. What makes this shop unique is that it has been created to attract  sukebe oyaji like me but also couples interested in discovering new ways to have fun sex. The Japanese artist Mizuno Junko has collaborated with several project produced by M's (actually I think this kind of collaborations are way cooler than the "traditional"  marketing projects made by KidsRobot or other so called streets brands). 
If you don't know this Akiba sex temple you should take a look to this  great reportage by Akibamap (translated by Sweat Pink blog).