To bring savory noodles to locales around the world, the operator of ramen chain Ippudo has had to adapt one of Japan's best-known specialties.

It took almost half a year to get the rich tonkotsu pork broth right in Europe because of the harder water. In western countries, noodles are made shorter so it's easier for the locals to eat. Chikaranomoto Holdings Co. may face its hardest challenge yet — bringing Japan's iconic noodles to some of the world's toughest foodies.

It plans to open its first Ippudo outlets on the U.S. West Coast this year in San Francisco and the nearby suburb of Berkeley, both home to competitive restaurant scenes. The company's March initial public offering raised enough to fund the cost of roughly two overseas restaurants, yet the chain is targeting the U.S. in a global push that will quadruple overseas shops in 20 countries in less than a decade, said President Toshiyuki Kiyomiya in an interview.