Right on Ninja-to!! I used to live in Tokyo and played D&D. Alas, finding other games was extremely difficult sometimes. The best gamers I ever played with were Japanese gamers willing to let me play with them despite their broken English. My Japanese was pretty good at the time so we communicated just fine. Those guys were a lot of fun.
Anyway, if you are looking for a good gaming shop in Tokyo, check out Yellow Submarine in Shinjuku. Just a short walk from Shinjuku station's Minami-guchi. Last time I was there about three years ago, they carried all the WotC stuff and a fair amount of other d20 stuff. Be prepared to pay about 1.5 to 2 times US cover price in Yen equivalent. English language RP games are an imported niche item that appeal to a small segment of an already small market.
Anyway, as to your question, I personally did not like the MM2 as much as MM3. IMO, MM2 had more exotic monsters that were less likely to see use in my game whereas MM3 had a lot more monsters that I felt would be easier to drop into my campaign. Take that as you will.
Good luck finding a group. My wife is Japanese and wants to return to Japan someday so I'll be looking for another group in Japan in a few more years myself.