See what I mean about school girl uniforms? This is the second unknown cosplay today, and I'm still as clueless as I was this morning!
I actually thought she was from Full Metal Panic! or maybe even Full Metal Panic? Fumoffu because of the overall color scheme. Now I’m not so sure because I think their uniforms had a red bow instead of the green tie she’s wearing.
I think her shoes are really cute though. Thanks to again to Viki for the contribution!
EDIT: Thanks to Princess Soup for confirming that she's Kisaragi Chihaya from THE iDOLM@STER!