Manga

So i was reading this manga a long time ago and i forgot the name, the plot is something like that:
There is people that can turn into a magnificent beasts and the are their "masters" who can control them. The first story is about a big black beast that leave his town to find his big brother that gone to look for his master (and found him), and in that time he get caught in some trouble but eventually find his master..
THANK YOU for anyone that help (づ￣ ³￣)づ