There are many reasons for going to Tokyo Station. Catching a train is only one of them. Ramen is another.
Technically Tokyo Ramen Street is not under the station, but in the underground subnade on the Yaesu side. Same difference, it's definitely worth knowing and spending time in.
If you have an hour or so to spare, then get in the line (30 minutes minimum) for Rokurinsha. If you just need to eat and run — which after all is the way ramen is really supposed to be — there's always Menya Shichisai.
The comparison is unnecessary. Shichisai does a very different style of noodle to Rokurinsha — Tokyo miso ramen. Here's a close-up.
Fine noodles, nice rich soup, excellent chashu, melting-good ajitama egg…
It's maybe not the best in this alley, but it's still pretty fine. I like the simple clean design too…
My one grumble: there's too much choice. Just look at the ticket machine…
[hint for English speakers: you won't go wrong if you just zoom in on the buttons that say TOKYO in capital letters. Those are the ones for Shichisai's classic miso ramen]
The places that keep focused on one thing and do it the best they can, they're the ones I seek out — just like Rokurinsha. Actually, you can't help but compare them…
More on Menya Shichisai (their main resto in nakano) on their website here…
And in English here…
Here's the Tabelog page...