The Kyushu-style noodle house Invincible Ramen is not short of confidence.

This can be seen not only in the eatery's name, but also in that the servers wear T-shirts emblazoned with the characters for mian hun, or "noodle soul", while bowls are imprinted with wu di jia, meaning, "invincible family".

This Japanese restaurant also has an open kitchen on a slightly raised platform, which makes the assembly line of ramen cooks look like actors on a stage. Cooks slice, pour, stir and fling with flair. All that's missing is a taiko drummer.

There's a very good reason for all this self-assurance. The establishment's rich tonkotsu, or pork bone soup, is a beautiful concoction. With a dense, velvety soup, Invincible Ramen proves it's not merely worthy of its marketing boldness - it's also worthy of repeat visits.

In fact, they could call themselves the city's best ramen, for all I care.

Located just north of the Renaissance Hotel, across the street from the Kro's Nest and next to a Food Cube, the restaurant is hidden in a commercial neighborhood that is searching for an identity.

During the lunch rush, businessmen in black suits and starched white shirts fill out the restaurant, while the crowd on calmer nights consists of more expatriates and families.

There are sushi, gyoza and grilled fish on the menu, which are all decent, but there's no need to order anything but the ramen.

The eatery's tonkotsu originates from the southern island of Kyushu, particularly Hakata-ku, Fukuoka. It's made from boiling pork bones, fat and collagen over a hot flame for many hours. According to one blog, Invincible Ramen uses 3 kg of pork bones for every three bowls of ramen.

During a recent lunch with friends, descriptions like "buttery", "milky", "hearty" and "creamy" were all uttered in between pleasant sighs.

The soup is filled with the usual ingredients - noodles, thinly sliced grilled pork, spinach, bamboo shoots and a fan of roasted seaweed sheets.

In the baijing chaoshao ramen (note to Invincible Ramen: shouldn't it be cha shao?), the tender pork is barely held together by strands of fat, while folding in the seaweed gives a momentary brininess to the meaty sweetness of the soup, which coats the lips after three spoonfuls. The only problem I had was that the noodles were not sufficiently springy.

If you have room for more, the tezhi rishi jianjiao, which veers more toward the US-style "pot sticker" than the guotie, had a good balance of chives and pork.

The tuna avocado sushi had a curious interior of tuna salad, lettuce and cucumber rolled in rice and topped with tuna and avocado slices. It was surprisingly not too creamy despite the dollops of Thousand Island dressing.

By far, the star attraction is the liquid pork. On a windy night last week, customers were quietly tucking into their bowls of ramen when, at one point, a table of four ended their meals in one sweeping tip of bowls to their mouths. As their smiling lips glistened, two waitresses nearby nodded in approval.