Responses

Yes, Candy is the real Yunjae. But the blonde is not fake, so it seems. They're both named Yunjae. There's actually no evidence that the blonde is faking an identity but in the raws, he lied about not being able to remember where he got the scar.
(take this next paragraph with a grain of salt, the translator i used is fucking up the dialogue) He is not a necessarily a bad person but he seemed to have caught on why Hajun is asking him about the scar and he is holding onto Hajun because of that.
FUCKING WHAT??? WAIT SO HE'S REAL NAME IS YUNJAE??? AND THE "YUNJAE (BLOND)" IS NOT THE REAL YUNJAE BUT INSTEAD LIKE FAKING HIS IDENTITY OR WHAT. IM FUCKING HELLA CONFUSED...