Shemale (also she-male) is a slang term frequently referring to trans women with male genitalia and augmented female breasts from breast augmentation and/or use of hormones. The term is considered derogatory by most trans women.
Shemales are common in Asia, especially in Thailand, where shemales often are reffered to as lady-boys. The main reason to why asian men becomes shemales are money. A shemale can easily make 1000 baht per night, which is about 4 times more than a regular worker makes.