@Randomizer "Street" clothes probably would have been a better translation there, as it's referring to basically anything that's not part of the approved school uniform, which a corset very much is not.
@Vasqueztion
Japan's take of vampirism usually goes more like "bood sucking devil(ish)" than the traditional "blood sucking undead", even moreso vampire is writen as blood sucking demon(oni) and being considered as youkai for some further muddle the waters