It took months to fully restore Aqua to her previous form. She barely remembers anything that happened after her encounter with the giant frogs. Everything went by in a hazy flash. All she knows was the soft, slippery, sticky sensation of the frogs insides and the sensation of swelling desires just before her mind blanked.
For Kazuma, that is very fortunate. After all, he was one of the reasons why her transformation was so difficult to reverse. The more a frog gets to indulge in their desires, the more likely it becomes that the transformation is permanent.
As much as Kazuma would have enjoyed the new, more useful Aqua, the earful he would've gotten from everyone else (except Darkness, she would've found it really hot) was not worth it.
At least now he knows where to find these frogs if he ever changes his mind...
Enjoy!~