Two particularly "fun" sites I have discovered are those dealing with my favorite chocolate snack treat, POCKY, and a second illustrating the process of Rolling Your Own Sushi (a related link briefly recounts the history of sushi, part of a larger site devoted to a many facited exploration of this food source.) 

Food fanatics will relish the set of luscious links accumulated by The Tokyo Food Page.  A basic guide to sake rice wine has been compiled by Izumibashi, a brewery located in Kanagawa prefecture (between Tokyo and Yokohama). 

The ultimate gourmet treat, however, might be to "order out" from Pizza Studio, the "typical" Japanese-style establishment in Michael Chachich's Tokyo neighborhood -- how does Squid Ink Pizza strike you? What we have here is the perfect illustration of just what can happen to cultural importations once they make their way into the Japanese cultural mainstream ... 

The traditional kaiseki-ryori meal often accompanying a traditional tea ceremony is described and illustrated at a site maintained by the NRI Cyber Business Park (just in case a business lunch unexpectedly places one before you). 

Chado, the Way of Tea, itself is considered in great detail by Kimiko Gunji, a professor at the University of Illinois at Urbana- Champaign.  (As part of Project Gutenberg, the full text of Kakuzo Okakura's classic The Book of Tea is also now available online.)