It's easy to do a soup test. Wait until you're feeling groggy, grey and brimful of winter. March unerringly – zombie-like, impelled – towards a bowl of soup. Sup, slurp and spoon it in. A good soup will act as a culinary hug to prod you towards health. Many soups do the trick: Jewish penicillin (chicken soup) is a winner, Vietnamese pho rocks and Polish tomato soup with a shot of vodka promotes healing and keeling over in equal measure. Also good is sustaining, nutritious Japanese ramen (noodle soup).

If I tell you there's a ramen museum in Yokohama you'll glean what a serious business this is. Ramen has a rich culture with myriad styles and protocols. Soup can be cloudy or clear, made with chicken or pork, then miso, soy or neither. Noodles may be straight or kinked, then there's the whole question of toppings.

Shyun focuses on tonkotsu ramen (pork bone broth). They also do a flavourful chicken base and most soups are offered with miso or soy as an extra layer of flavour. My pick for busting a winter lurgy is the pork gekikara. The broth is opaque, sticky and rich with collagen; it's piled with springy noodles, spicy pork mince, boiled egg and corn kernels. The chicken karaage (with crisp nuggets) is good too.

The experience is perfunctory. Customers are crammed in, turnover is quick, and if you want somewhere to put your bag or coat you'll have to use the gardening bucket wedged under your stool. It's not unwelcoming though: jaunty signs give newbies the lowdown on eating rubrics (DIY seasoning, eat noodles last) and there's a change table in the toilet if you're brave enough to bring baby.

There's other food too but the dumplings and rice dishes aren't a patch on the soup, either in flavour or magical healing properties.

Rating: Three stars (out of five)