I kind of feel like this was a missed opportunity to have Ponko replace Yachiyo in the OP.

I am traveling right now, so I am going to keep it short. I wasn't really feeling this episode for a while. Yachiyo going through a rebellious phase (no matter how hilarious or well animated it was) felt a bit out of character to me. However, they brought me back around with the emotional exchange between the two. I am going to miss this show when it is over.