Hippo when he's a cute boy with his reformed Cute Witch girlfriend Yuuri.
Also, when the two first met, Yurri cuts her foot while walking on the beach and Hippo wraps it up in bandages. Later, Hippo tries to get a job so he can buy some shoes for Yurri and succeeds at the end.
The series finale episode, Gaito returns alive and well and alongside Aqua Regina. Both tell the Princess's that it's okay to love humans and that they should all sing for their happiness.
Even if the canon of it is flaky, watching all of the reformed villians restored was very nice to see.