1. Adam (Ainosuke)- he's a politician by day, sex offender on a skateboard by night. Plus he has a whole ass matador costume and wears a mask that literally hides his face. Even as a teen he wore a hood to hide his face. He keeps his double identity well hidden, to pretty much everybody except Tadashi.
2. Cherry (Kaoru)- like Adam, he wears a face covering, but on the bottom half of his face. He also wears his hair up and wears contacts and has an entirely different outfit for skating. He's gotten mad at Joe for using his real name at "S", and at Reki for using his "S" name in the real world.
3.  Shadow (Hiromi)- initially, I ranked him higher than Cherry based on looks (his shadow persona is very different from his civilian self), but then I remembered that he regularly shows up to "S" with his VERY DISTINCTIVE pink car that he uses for work. He can try to cover up the little logo of his work place, but c'mon. It's a pink car.
4. Joe (Kojiro)- Joe's "S" outfit is... being shirtless? LOL he's not doing much to try to hide his identity looks-wise, but still has an "S" name he goes by
5. SNOW (Langa)- Langa doesn't really have an "S" outfit, so he ain't hiding. However, his clothes are pretty plain and non-identifiable so he could easily hide among a crowd. He has an "S" name but doesn't really seem to acknowledge it (then again, he doesn’t seem to acknowledge anything- Langa really said head empty, only Reki). 
6. MIYA- his "S" name is basically his first name so he ain't hiding either. He wears his infamous cat-boy hoodie when he skates but that's probably cuz he doesn't want to get his school uniform dirty. 
7. Reki- this boy isn’t hiding anything- he showed up in the FIRST episode in his work uniform to deliver a skateboard. Reki really said fuck privacy I'm coming to "S" in my SCHOOL UNIFORM and you will address me by my REAL name. boy might as well be passing out his home address and social security number, smh. 

nothing to see here, just two tired anime men taking a nap