Sounds like a concise summary of Doremi as a whole! Speaking of delivering...
Ojamajo Doremi Na-i-sho 13 END
Yamauchi had his landmark ep in 4, Sato had 12, of course Igarashi himself wouldn't be left out. Well, he had 9 but that was a different kind of episode.
It's amusing that both 12 and 13 boil down to the same set-up of Doremi -and only Doremi- meeting and interacting with a new character, and how different they turned out from there. It speaks to the strength of the series -and this OVA in particular- that both are fucking amazing. Na-i-sho was fucking amazing, best animu I've seen in a good long while. I don't know how I'll go back to regular Doremi now, as good as that is