The bright yellow sign calls down over the busy, narrow sidewalk like a grandmama from the old country exhorting her brood to come to table. "EAT EAT," it shouts. Do as you're told: Go in and sit down. We did. And we ate. We ate very well indeed.

Apart from the neon up above, there's little to indicate this blink-and-you-miss -it hole-in-the-wall diner is anything special. But, as we've learned so many times in this city, you don't judge a restaurant by the width of its shop front or the length of its history.

Eat — for that is its punchy, no-nonsense name — only opened last summer, but it didn't take long for the word to reach the street: Tokyo's got a hot new "premium burger" joint. We found out it's got a lot more to offer besides.