Ōsaka - Namba: 551 Horai Namba - Buta-man
A butaman (豚まん), the Kansai variety of the Nikuman (肉まん), is a steamed barbequed pork bun. While the steamed pork bun is a widely available Chinese food, the hand-made butaman is sold excluisively in Osaka and surrounding area.
551 Horai Namba sells what many consider to be the buta-man, a barbeque pork bun, in Japan. They sell in excess of 100,000 a day.