@Smil1 then i guess its a good thing this contained no filler. As the term "filler" implies, everything you just witnessed had nothing to do, and no impact on the main plot other than to pad out the viewtime.
The naruto gang chasing kakashi around trying to see his face, and then making no mention of that in later episodes... is filler.
Giving explainations, introducing new antagonists, and pushing the main character forward in his adventure... is not filler.