You crave REAL Japanese ramen soup? I can understand that, but the flight from Zurich to Japan is simply very long.
But now there is finally an alternative in Zurich near Europaallee: the Yume.
The small restaurant could really have been beamed directly from Tokyo to Zurich. You are even greeted in Japanese (very loud and friendly) and said goodbye again when you leave.
The ramen broth was just wonderfully spicy, the onsen egg is cooked perfectly and the noodles are almost the minor matter in the whole dish. Make sure to reserve for lunch or come early.