My Name is Luka (More Than Friends #7)
Aria Grace

Each book may be read as a stand-alone. Reading in sequence is not required.
Brad spends his days swinging a hammer and his weekend nights pouring drinks just to keep his nose clean. At only twenty-one, he's already had enough trouble to last him a lifetime. But when he realizes the boy upstairs has new injuries that coincide with loud shouting matches from that apartment, he knows he has to do something to help.