It couldn't be more obvious. It's fucking about a Samurai. Plus, the artstyle.
People forget that Samurai Jack was the second American Cartoon to do the clean vector-style artwork, Powerpuff Girls probably being the first. Coincidence? No, they're the same Art Director. He also did Star Wars Clone Wars and *Dextor's Lab*. Same guy, Genndy Tartovosky. He started this whole pseudo-anime style.
But Samurai Jack was clearly his cartoon most obviously influenced by anime.
And now you know.
The sad thing is he's pretty much refused to do anything else now. He's pissed off that CN didn't treat him the respect he deserved. They cancelled his best show (Samurai Jack) and are just generally a pain. He's pissed.
He almost made one more show, I would highly recomend it. It's his only adult cartoon. There was only a pilot made but then he said "fuck you" to CN again and it was cancelled. Yet, it is the single most epic fuckwin cartoon CN could have ever hoped to make.
Korgoth of Barbaria. Watch it.