I don't know what Nostalgia is, but when I searched the image it comes up with a character named Raika Oda. This artwork was referenced from an image I downloaded from a Danbooru, wasn't sure who or what she was. Ended up redrawing her in high-res from scratch. Is this an original? no. If you do find out who she is, let me know.
The word nostalgia means to have strong feelings for things that we appreciated in the past like watching an old t.v. show or playing an old game. I was renfrencing a show on the Internet called the nostalgia chick, a female counterpart to the nostalgia critic. The two shows can be found on thatguywiththeglasses.com. The person who does the nostalgia chick looks strikenly similar to what you drew. I just felt like pointing this out as it was so mind blowing to me. I hope this clears the confusion and that you have a safe day.