In this day and age you still see people saying stupid shit without Googling it first. Literally hundreds of real-life results for this sweater. The hype to draw your characters in one came after the initial real-life hype.
I have a feeling that it is real, and could be used as a fashion statement as an outer-wear sweater over something else. I think it'd look cute that way, but yeah, would be nice to see it as a stand alone~