This girl I'm pretty sure I've seen somewhere before. Maybe not the cosplayer, but definitely the character, but I can’t seem to think of which series she belongs to at the moment.
Guess I’ll have to rely on my Cosplay Holic readers to give me the answer this time. Anyone care to point me in the right direction? Thanks to Gilbert for sending this in!
EDIT: Thanks to anon for commenting this is Houjou Satoko from Higurashi no Naku Koro ni!