According to a widely circulated YouTube video created by the advertising company Dentsu Tokyo Inc.,
They assumed the reason for this gender discrepancy was because in Japan, it's attractive for a woman to have what's known as an "Ochobo" - a small mouth that one politely, and modestly, covers when open in public.
So Freshness Burger and Dentsu invented what they have dubbed a "Liberation Wrapper," a burger wrapper that doubles as a face mask with the picture of a woman smiling politely.
According to Freshness Burger, after introducing the sexist wrapper, sales of the "Classic Burger" rose by 213%.
Check out the video for the new burger mask below.