Shigeru Tamura looks remarkably trim for someone whose hobby is eating fried noodles. Over a lunch at a yakisoba restaurant on the backstreets of Tokyo's Shibuya Ward, the 49-year-old author and law professor admits he dines out as often as twice a day. Then he pushes aside his plate of noodles and pulls a digital pedometer from his trouser pocket.

"I try to keep slim by walking a lot," he says, and frowns on seeing that today's tally is stuck at around 4,000 steps. "I usually get in around 10,000 each day."

Tamura's travels haven't always been on foot. While working for the then-Ministry of Home Affairs in the 1990s as a liaison officer for local governments, he visited every one of Japan's 47 prefectures — at least four times. That experience has served him well in his current position as a professor of political science at Niigata University Law School, and, combined with his passion for local cuisine, he's emerged as one of Japan's most sought-after commentators on the phenomenon of B-kyū gurume (B-grade gourmet).