What-a-waste Man (Japanese: もったいない男,Mottainai-otoko) is the 4th episode of the Yo-kai Watch Shadowside anime. It was broadcasted in Japan on April 27, 2018.
Recently, posts about a strange incident called “What-a-waste Man” have been increasing. It’s rumored that What-a-waste Man inspirits children who leave behind food while and then, the weakened children keep on losing weight and end up dying. Now it's up to Summer and the others to solve the mystery of the What-a-waste Man.