Identity/Gender Change

Hello! I have a question regarding a friend of mine who is a transgender (female to male) - no surgery yet top and bottom, just taking testosterone. He looks like a man already bc he's been taking T for years already. For some reason, he was able to change his full name, get new legal documents with his new name and gender (birth certificate, government ID's, passport) to his new name and identity. Only a few people knows that it is not his real name and identity.

Now, his gf is applying abroad as an international student and he wants to come with her. Will he be able to pass through everything without them knowing that he is born female? If they did, will it be an issue? What will happen to them if someone from the law knows what he did?

Nakalabas na sya ng bansa and used his passport already a few times (Korea, Thailand, Malaysia)

Thank you!!