This is a complex answer and you can get more info via a good Google search.  In Japan, they have Blow Job Bars, SoapLands, and more. Basically, everything other than intercourse is legal.  You can get a room and do everything, other than intercourse at a reasonable price. You can however find straight sex at many soaplands. In Taito district of Tokyo, north of Asakusa Shrine is a large area with lots of brothels. Be careful, as most do not allow foreigners.  

My advice is to use the legal services that provide a menu of girls. Pick one, get a love hotel for an hour and have fun.  These are much better looking than the ones you get in the brothels.  Learn the customs, as all girls require an odd bathing process at the start of every session.  

Send me a PM and I'll send you more info

On places to travel to, I would not pick any of those.  I've been to a couple of those places, but the only 2 places in Asia that I thought were at least half way decent, was the countries of Thailand and Phillipines.  I'm in Panama, getting ready to head to Columbia.  Happy hunting.