Why Japan? what do you want to do on your trip? Japan especially Tokyo is insanely expensive.No lie it is man I got smoke coming out of my ears on this one
I wouldn't go to an Island outside of Trinidad, Jamaica Cuba or the DR without a girl but that would be a nice short trip to get your toes in the water.
Canada would be even better (in the summer) I guess Costa Rica or Panama would be Ok too. Panama uses the US dollar so it's easier to aviod being over charged.