the Land of Bob

Of course, the Japanese corporeal form being typically less voluminous than the American or British form (this is a good thing for them, in general), the riders of most of these probably don't qualify for quality saddles such as the RealMAN (R):
http://sheldonbrown.com/real-man.html
Check it out - I'm offering a free drink* for the first person to spot one in production use on a native Tokyo bike.
Avid cyclomaniacs should also be sure to check out other ShelBroCo products, such as the FasterCard(R), or the Product W amphetamine-free performance enhancing product (check it out for your next marathon or shagathon - does the trick for me - I managed a 27.43m jog** on my treadmill, fueled by nothing other than a 28-tablet dose of Product W, and 55l of water. Furthermore, I managed it after eating a spaghetti bolognese, and a whole Battenberg Cake, which theoretically should have slowed me down by destroying my normally aero-dynamic profile).

Well, gotta dash - time to mount my RealMAN and get those legs PUMPING ...

* In fact, I have every faith in your ablity to do this. Pre-emptively, I'm going to have a drink for you weekly until you deliver the goods.
** Technically, 30 yards***: I converted to metric to cater for your international readership.
*** about 89 shaku, for the traditionalists amongst you who, like me, believe that metrification was the thin end of the wedge.

YOU'RE a bike