YeinJee's Asian Journal

Nakizumo (lit. crying sumo) is a traditional Japanese festival with 400-years of history. The event, believed to bring good health to the babies, is held annually in temples across Japan where the kids would face-off each other to see who’s crying the soonest (and loudest)…

The above video [credits to garyjpn@youtube for the upload] is probably from Hiroshima in 2009; there are other slightly different format in other places, including in Tokyo where some real sumo wrestlers were involved.