Have you ever seen the Woody Allen movie “Radio Days”? In it, Woody grows up with his family, living snug-as-bugs in a tiny room underneath the Big Dipper on Coney Island. Every time a roller coaster careens overhead, the walls shake and objects pogo off the tables. Of course, nobody notices. It was funny. And it’s the only thing I remember about the movie.

While the Yamanote Line is hardly a roller coaster, it does do a horizontal loop-the-loop around Tokyo. And when I first heard of a bar tucked under its tracks in Shibuya, the thought made me smile. And then, once I had installed myself at the bar — listening to some chill acid jazz, martini in hand — a train rattled and screeched overhead, and I nearly fell off my stool, laughing.

P-chan chats with a customer.

Underline, as it is known to most, is one in a short string of stores, each about the size of a railway-carriage, which lean into the embankment on the southwest side of the tracks. It first opened four years ago as Milligram Underline — the first half being a play on the names of the two women who managed it: Michi (milli) and Gera (gram). During that first year or so, one would always find it pleasantly alive with cool, fun-loving people.

When the girls moved on, Konishi-san, the leaseholder, thought he’d try his hand. He ripped out half of the street-front wall and added some big bamboo blinds and a couple of long braziers — the latter solving the heating problem in winter, while serving as barbecues year round. Suddenly, the girl behind the bar was sporting a miniskirt and a pout, and the customers were wearing chains. It became a rock ‘n’ roll izakaya with a nervous, etchi (sexy) edge.

But even that phase is now ancient history, as it recently changed again. I knew something was up when I found it closed one night with a sign saying it would stay that way for the rest of the summer. But like a chrysalis on rapid-growth hormones, a few weeks later it reopened — transformed and refreshed. It is now officially known as 4, in honor of the number of the platform under which it stands.

P-chan, the new master, is a quiet unassuming guy who easily shrugs off questions. It is obvious, however, that he thoroughly appreciates and understands his unique new home. He has ripped out the ceiling to reveal the raw concrete underbelly of the tracks above, complete with heavy metal ribbing and bracing. He has also completely exposed the embankment wall, with its distinctive JR brickwork. Footlights throw gentle arcs of light across uniformly white walls. The only color has been applied to an outcrop of concrete along a side wall, which has been rendered in a pretty Miro-esque blue, as a stylish reminder to watch your head. The effect is minimal and elegant.

P-chan has collected his own clientele in a decade or so of bartending, but he also knows Michi and Gera, so 4 includes some familiar faces, too. His preference for rare grooves and reggae is also a common thread. So, in case you were at first disappointed to hear that Underline had closed, don’t worry — you can still get to know and love it in this life . . .

In line with COVID-19 guidelines, the government is strongly requesting that residents and visitors exercise caution if they choose to visit bars, restaurants, music venues and other public spaces.