Why do you care about guys messaging you online? It's not like they're going to virtually tap ya'. Go out to a gay bar with some friends and meet some actual potential.
In the meantime though..post one of these un-returned messages, and I'll tell you what's wrong with it.
This is pretty much all I send them.
hey, how are you?
my name is Mayu
Alright, I see our problem here.
#1. "hey, how are you?" is a dead end conversation anyway. You're really stressing over the "Good, You?" that you'd get back?
#2. Don't tell him your name. He doesn't care because he has no idea who you are. If he shows some interest, then get into that shit.
Your name is also pretty left field, and he might think you're this weird foreigner. Show him that your name is unique, AFTER he's established that you're fluent in English.
#3. Fire him a compliment about his profile or picture, then end with a question. He'll feel bad if he doesn't answer because you were nice to him.
ie) Hey, your profile is hilarious. How was your New Years, man?