I think it adds to the character's appeal.  She's not quite connected to reality. The whole childlike innocence thing in the tradition of Peter Pan or Pee Wee Herman. It just enhances the over the top enthusiasm of Japan that they're trying to parody. And I think they're capturing that pretty well. Watch any game show over there, or anything with Hard Gay. Kiko isn't that hard to beleive as a character when viewed in that context.