[Zenigata nods, having no idea what the Captain is talking about, but getting the feeling that Luffy really is more of a troublemaker and less of a common crook. When he starts talking about Lupin, his voice starts out a mumble, gradually rising as he gets more impassioned.]

Why am I chasing Lupin? Because its my job. I'm a police man, and Lupin is a thief. He causes all kinds of trouble, wrecks important monuments, steals from people, and is in general just a nuisance. He's not a violent criminal, like some people, but he's still a criminal and as a cop its *my* job to bring him in. Being a nice guy doesn't make him any less of a thieving bastard. I made it my life's goal to bring him in, and I will do it.

[He grudingly respects Lupin for his intellect, and knows Lupin feels the same way. They've been at this cat and mouse game forever, but deep down Zenigata knows...that he likes the chase more than the prospect of actually catching Lupin]