Dosu is Anon's pet. The gutter trash keeps gathering because they think the dosu will protect them(Which generally amounts to servitude) Mister and Dosu kill the congregating shitheads.
This Anko story sure looks interesting, may a request a translation of it for the Yukkuri Fanfic Group? It seems to have potential and some degree of originality. Specially if the story is what Matt theorized.
That's generally how it works in these stories. A Dosu is (By yukkuri standards) Something that let's yukkuri take it easy. As most yukkuri see taking it easy as being lazy assballs, that generally a dosu is gonna be taking care of the needs of a bunch of lazy, stupid, abusive, and arrogant retards.
I feel sorry for them. Anon and Dosu, that is. It seems there is actually a limit to how much entertainment you get from smashing yukkuri. Then again, doing the same thing over and over again will get tiresome eventually.
Matt is on the right track, but instead of dosu being anon's pet, it's acutally more like his brother, since they were raised together by the same parents.