I finished reading this series some time ago, and I have to say that it excceeded my expectations. It was a very well written story with excellent characterization. The collection is only 20 or so volumes long, so it's good for someone looking for a decent read that won't take too much time nor leave you craving more.
You main hero, Train, used to be part of a deadly organization, but left to pursue his own destiny. Although he tried to leave his old life behind him, he could not escape it, and now, working as a sweeper (or bounty hunter, if you will), Train Heartnet is forced to confront his toughest target yet, his old partner.
This is a very general opening, and it doesn't even touch how deep this series really gets. There's an anime based on this series as well, but I have yet to watch it. (From what I hear it isn't too good though.) This is one of the few manga I would encourage anyone to buy as opposed to reading it online. Trust me when I say you will want to read it time and time again.
