Origin of this fake image?

I saw this pic on idolfap.com. Her face is a fake image of Korean Idol IU, so I wanna know the ORIGINAL source of this image. The uniform she wears is from Japanese mobile firm 'au by kddi', so I'm pretty sure she is Japanese. The letter on this uniform is straight, so I'm sure that this image is not mirrored or reversed. I've found such a girl in this kind of uniform is called 'campaign girl' or 'booth girl', which is キャンペーンガール or キャンガール in Japanese. I've been googling based on this information, but I have no idea of this girl's name or such image source so far.