On a different note, Yellow Submarine is also the name of a chain of role playing game stores in Tokyo. They also sell Trading Cards, Model Kits, miniatures as well as european boardgames. most of the stores dealing only with one of these markets, but all operate under the same name, which makes it difficult to know weather this is the store you want from the outside. So far, I've seen multiple stores in each Shibuya, Shinjuku, Akihabara and Ikebukuro, but there are probably more.
The chain seems to be operating for quite some time now, so you can usually find loads of OOP game materials from way back. For example, recently I found a couple of Grenadier Traveller miniatures that were produced back in 1981.
As other FLGS are scarce in Tokyo, the Yellow Submarine is often your best bet for new game books. The prices are quite stiff compared to the US, but most of that is probably import costs. Good place to keep your gaming hobby alive even in Japan. And they carry KoDT as well! Hoody hoo!