For the fourth time in as many hours, Ataru went flying >across the
restaraunt.  He landed, roughly, on the floor, at the feet >of four very
familiar looking individuals.  Ranko lowered her fist and >stomped back
into the kitchen.

	Have you ever seen the UY OAV Nagisa's fiancee?  In it 
Ryunusuke(Spelling?) is introduced to his fiance Nagisa.  At the end of the 
episode Ataru and Mendo sudenly realise that for some reason neither of them had 
made any attempt to make a pass at Nagisa.  It was then revealed that Nagisa's 
father had wanted a daughter just as much as Ryunusuke's wanted a son.  Of 
course while this would let Ataru spot Tsubassa's disguise, it's possible that 
since Ranma physically changes he might fool Ataru.  Even so, it's likely that 
Ataru will feel some ambivilence toward glomping Ranko. Just a thought, feel 
free to ignore it.