The first thing you notice about Aozora Blue, chef Hirofumi Matsui's Michelin guide-listed udon noodle restaurant in Hiranomachi, Osaka, is that it doesn't really feel like an udon restaurant. It's DNA is much closer to that of a soba restaurant.

That's both deliberate and understandable. Prior to opening Aozora Blue at the end of 2014, Matsui had spent the previous 15 years making soba.

As Matsui, 44, recounts, the first time he ate at Dosanjin, a soba restaurant in central Osaka where noodles are made by hand, he was "shocked at how good the soba was."