I lived in Japan for a few years and consider myself reasonably aware of the culture and whatnot, and five cities in a week still seems nuts to me - it'd be barely enough time to walk around the local train station area, go somewhere to eat, sleep, and then head on to the next location. Might be OK if you're limiting yourself to "cities in Kyuushuu" or similar, but otherwise has the ring of "I ate at Applebee's in Times Square! NYC is soooo great!" about it.