It wasn't too long ago that Blake had become a one-star Hunter, thus officially joining the Altered Hunters. Of course, now that he was officially recognised as one of their members, there were certain responsibilities on his shoulders.
No longer was he able to just travel and piggyback with his father doing hunts in the local area. In the first place, Ozacas Hunt was away more often, being called by the organisation for important tasks involving the mysterious black liquid.
This was one of the responsibilities of being an Altered Hunter, to always answer when they call you, and it was why Blake was where he was now.
Of course, hunters could choose where they wished to live, and they could also act as they saw fit, as long as they followed certain guidelines that were given out, but the guidelines weren't the set law.