It's no secret: Ramen is big in America, and getting bigger fast. It also seems to be undergoing some unusual mutations in its new, no-holds-barred environment. No one understands this better than the self-styled "hyper ramen creator," Tomoharu Shono.

He's the man behind some of Tokyo's best and most innovative ramen counters, chief among them his flagship store Mensho, in the Gokokuji area. He also has an outlet in California, called Mensho Tokyo, that draws long lines and even has a mention in the local Michelin Guide.

Now Shono has reverse-imported some of the recipes he's created for his U.S. clientele and he's got a bright new outlet to serve them in above Shinjuku Station. A warning though: If you head to Mensho San Francisco looking for classic shoyu, miso or shio ramen, be prepared for disappointment.

The basic bowl is the Tori Paitan, a thick, white, chicken-based soup creamed up with soy milk. This also comes in vivid green (Matcha) and deep orange (Spicy) variants, although the latter tastes more of tomato than chili.

But the stand-out, top-of-the-line bowl has to be the A5 Wagyu Shoyu Ramen. This comes served (after 5 p.m.) with a generous slice of rare premium beef draped across the top in all its marbled glory. Straight out of Nob Hill, straight onto Instagram.

Ramen from ¥860; Japanese menu; a little English spoken