That depends, in the manga he mentioned how he had saved several 
women from wild beasts then ran away from them because they wanted to 
know his name.  He comes across real feirce and self confident, but his 
shame of his own name seems to have kept him from geting to close to 
women in the past.  So his unease isn't all that unusual.

Nervous about women showing an interest in him, yes.

Nervous about Ranma showing his chest - IMO, no.

They're two *very* different reasons.



---
Ronny Hedin, thark@hem2.passagen.se, http://nabiki.newberry.edu/thark/
        "So, they aren't extraterrestials?"
        "Nope, they're manga characters who've lost their hair."
        (the unexpected end of X-files)