I will also admit to being intrigued by SAMAS's advertisement of Argevollen. I will also have to try it out.
Jiggy? Why wouldn't you show it to children? One Piece character's have a sort of child like mentality, are drawn in a child like fashion, and seem to be made "cool" in the way a child would make them cool. The violence is pure cartoony and I didn't notice any adult situations, language, or nudity in the various episodes I have seen. Heck I haven't even seen any romance or even teen drama in the show. I would say from what I have seen that this show is solidly marketed to young children.
That isn't to say I haven't been shocked by an adult fan following for other children's shows; MLP I am looking at you.
I could understand a bit of it. Some of the situations can be a little difficult to explain to children.