On the fourth Sunday in April, Japanese parents descend on the shrines of Tokyo with their bundles of joy, which they promptly hand over to a sumo.

The two rikishi, babe in hand and weighing over 150 kilograms each, step into the ring. In a normal bout, they'd collide, trying to push each other out of the ring, but on this afternoon, it's the two infants that are the competitors.

This competition is all about seeing which infant can cry the loudest.