I'm really not sure what other suggestions can be given. You can take a compass and draw a circle around Shanghai measuring a 4-hour flight time. Saigon would seem an obvious choice from what others have written - but it is a little outside your limit. You're really stuck with China, Japan, Korea (South and North should you be so minded), Macao, Myanmar, Laos, much of Vietnam and Taiwan. There's plenty of rent in Tokyo and Osaka. You just need to look at the various rent bars like Kings of College in Tokyo. But if you don't know your way around, don't speak a little Japanese or have a Japanese gay friend, you will likely end up pretty frustrated. I've chatted with a few non-commercial guys from Macao and expect there must be a rent scene there given the prevalence of the casinos and masses of holidaymakers. I have a lot of first hand experience in Taiwan, but not with rent. Indeed, there seem to be very few MBs on the apps. I'd still go with Manila where there is a rent scene and no language problem.