ARuFa demonstrates how how he created a fart cannon, using a cardboard box, a hose, and his ass to create what he's dubbed a "onara tobashi ki" or "fart-firing machine."

So, you cut a hole in the box, which is easy enough.

Then, you cut a hole in your underpants, which isn't easy enough.

Next you equip the tube. Yes. Equip.

And insert that tube into the box.

Here's how it apparently works: You fart, and the tube transmits your stink from your bunghole to the box. Then, you hit the side of the box, and that fires the fart. Like so...

So, find volunteers or unsuspecting friends victims? for fart launching fun.