This and the following chapter were adapted together as the 5th OVA in the OG anime. It'll be adapted in the Remake too.
You can tell where Takahashi got the idea for fiancés and arranged marriages from for Ranma 1/2. It's obvious.
Nagisa and "her" father might be bigger idiots than the Fujinamis. At least Ryunosuke seems to have a normal head. But the Shiowataris are both idiots.