A Tokyo restaurant is marking the crowning of the new Japanese emperor next month with a US$900 football-sized, luxury hamburger. The burger, which is dusted with gold flakes and topped with foie gras, slices of Japanese beef and freshly shaved black truffles, went on sale at The Oak Door steakhouse in Tokyo's Roppongi district on April 1. The pricey “Golden Giant Burger” commemorates the coronation of Crown Prince Naruhito on May 1 and the beginning of Japan's new Reiwa Era.