Yeah, Japan is awesome.
Pro's and cons? Well, you'll never come acrosss a seedier section of metropolis than roppongi, I swear I thought i was hearing things when 100 Aussie accents hollered "tit's and beer guys!" at us from 100 yards out.
Nakano is fanboy/girl heaven with so much collectable shit I always wish I brought another suitcase with me.
Shinjuku is an ace night out if you don't fancy roppongi, Darts bar's are the shit - generally, the Japanese suck at 501 but I never won a single game of cricket
Other than that, people disappear, get killed, shot, stabbed etc etc much like every other country - the difference is not a lot of Japanese people speak english and it can feel pretty isolating sometimes.
But its like any place, it's what YOU make of it - so do the deed and book a plane ticket.