Join Date: Jan 2007
Location: Tokyo, Japan
Device: PRS-500, HTC Shift, iPod Touch, iPaq 4150, TC1100, Panasonic WordsGear
No. He won't find any eBook devices that are comparable to the Reader or Iliad, for that matter the only eBook devices he'll likely see are the standard all-in-one dictionary, thesaurus, encyclopedia, and translator device. Contrary to any news articles or web blogs you might come across, the Japanese haven't really embraced the eBook concept yet. Yes, I know the first eReader device from Sony kicked off over here and not in the states or Europe; i.e., the Librie, but due to a highly flawed marketing strategy and just plain dumb DRM scheme, it didn't take off as expected; hence the reason you'll be lucky to even see the newer Sony Reader in use over here. This isn't conjecture, I've been here for almost a year now and routinely visit the electronics district, second-hand electronic shops, and local gadget watering holes and have seen neither hide nor hair of an eReader, save for the style mentioned previously.
Some things he might see that are interesting are tons of Sharp Zaurus's, loads of DIY robot kits, more surveilence gear than you can shake a stick at (you'd think James Bond shopped here, or they don't trust anyone too much here (which they do)), lots of cheap, literally speaking; i.e., junk from China, electronic components, even more flashing & spinning lights, and lots and lots of cameras and Personal Media Players (PMP). All in all, it's fun to go look at but your brother won't be finding too many bargains that you can't already find off the Internet; if he's lucky he might find some cool gadget that hasn't made it to the West yet, but stuff is just not that cheap here. The best prices are to be had at the used/second-hand shops, where you can pick a very delicately used laptop on the cheap (quite possibly one not released outside of Japan). I picked up a sweet laptop that was a few years old, but is the lightest/smallest notebook on the market bar none. It was released (actually imported to order), and still draws a pretty penny, in the US about 6 months after it was available here, but I only paid ~$700 for it.
There's so much more to tell, but your brother should be warned that Japan is not cheap by any stretch of the imagination, so don't expect to find super awesome deals, especially if it's something newly on the market. Hope he has fun and has a safe trip!