Ah! If You're a Real Man, Save the Goddess!?

Urd and Skuld leave to do some work back at heaven. Skuld has Keiichi eat some flan which transforms Keiichi into a woman. Now he'll keep his hands off Belldandy, right? Keiichi and Belldandy go through Urd's potion ingredients to find an antidote but the formula goes wrong and Belldandy catches some kind of flu, and it's getting worse!

Synopsis excerpt via Kitsu.