get a guide book... 
if u're going tokyo, basically u can go shibuya, ginza, disneyland
this kind of shopping places and gia gia....
u can also go osaka with shinkansen and sapporo in hokkaido, though
it's better to fly there.
u can also go to their shrines and monuments to see see....
if u're not going as a package, get a tokyo rail pass in singapore
before u go there. prices are about S$550 for one week, but i
suppose it'll save u a great deal over there. valid for JR
railways, but generally not for monorails and subways.
