Last week a pop-up shop emerged in Tokyo’s Harajuku district called Fast Food Aid. Looking somewhat like a sleek laboratory, the door had a large orange cross and the window was lined with orange prescription medication bottles. A neon sign glowed with the words “For FREE.”

What was being given away for free were vitamins to supplement the nutrients people weren’t getting from eating typical fast-food like burgers, pizza fried chicken and ramen.

All you had to do to get your free supplements is bring in a receipt for any fast food purchase, which was not difficult considering the abundance of burger joints, fried chicken shops and gyudon (beef bowl) restaurants in the neighborhood.

Lab “pharmacists” would then analyze your intake based on the receipt and give you a bottle of vitamins and nutrients to supplement what was missing. “To fast food lovers, who is also health conscious,” reads the tongue-in-cheek slogan. “No need to worry! Just take our supplements after eating your fast food.” By placing vitamins into the hands of fast food-eaters the entire process was meant to visualize the detriments of fast food.

Behind the elaborate yet clever pop-up shop, which was open for just 6 days, turned out to be an unsuspecting and ironic mastermind: a Japanese fast food chain called Dotonbori. Except, instead of Japanese fast food like ramen, gyudon and takoyaki, they offer okonomiyaki and monjayaki: pancake-like foods that are considered a healthy fast food because they often include fresh vegetables. In fact, the punch line comes at the end when the medication bottle for okonomiyaki is presented as being empty. “Looks like fast food. But 0 tablet”

We’re not entirely convinced that okonomiyaki are the cure to modern unhealthy eating habits. They’re typically served with heavy sauces and mayonnaise loaded with sugar and fat. However, they certainly provide a more balanced meal than most fast food and this clever campaign, which came to life with the help of design studio Kaibutsu, helps make that point.