Naruto & Sasuke vs. Fun as a Concept

Current Naruto and Sasuke are transported to our world. Their goal is to eliminate the concept of fun. In order to succeed no being on Earth may experience fun for at least 24 hours.

Start in downtown Paris.

Chakra equivalency is on as are morals.

If they could somehow perform the Infinite Tsukiyomi that would be a way to do it, but aside from that...