Even I knew Bayonetta's costumes were made from her own hair... except in Bayonetta 2 I guess.
What do you mean 2 is different?
She still shows some skin when attacking in 2.
Still of course depending on what she wears.
Both in Bayo 1 and 2 there are outfits that are not made with her hair,
and thus will not come off when she uses her hair to attack.