Perhaps the "man bun" style was popularlized by hipsters, fey film types & fixie riders, but it certainly didn't start there. I recall reading descriptions of men wearing "top knots"... (a far better term, imho, when worn right. 'Man bun' is clearly derisive and hopefully refers only to hollow fashionista followers) ..back in cyberpunk novels of the late 80s. I suspect it came over here via novelized references to japanese samurai / yakuza styles.
top knot + mustache = no.