I would think that by the 5th episode they would have quit with the intro for Oga. I really see no reason for it. If you are only picking the show and starting with the 5th episode then you are missing some information that helps in understanding what is going on. I think that they can stop putting in the intro now. Now on to more important things. Oga now has some weird marking on his hand because of a contract formed with Baby Beel. Why is that everything involving demons has to have a contract? The marking grew and it kind of creeped me out. It should not do that.
It would seem that Himekawa is the next member of the Ishiyama TKKH that Oga had to encounter. To me it looks like Hilda just lets herself be captured to test Oga and see if Baby Beel still wants to be with him. I can almost guarantee that Hilda could take of the problem if it involved humans. She is a demon after all. The only real reason that Himekawa wanted to meet Oga was to try and recruit him. You never try and recruit someone after you have harmed their friends or family. Oga is not a negotiator either. That makes me happy a little bit. This has been Xly15 and check back later for more.