Yume ramen is authentic Japanese ramen. It's 3 times the price of what it would cost in Japan, but it's proper ramen, yummy!
https://www.yume-ramen.ch/ Samurai II is known for great sushi (Japanese chef and service staff too), but they have a lovely authentic every-day kind of dishes. Have a look at their menu.
https://www.samuraizwei.ch/menu Bimi. Also Japanese-owned (same owners as the Japanese supermarket Nishi). Tastes exactly like back home. Just more pricey than the above two.
https://www.swissbimi.ch/
All of these places are easily reachable from HB. I can only speak for Japanese food for authenticity, but the above three places many of us Japanese go there.

One place we definitely stay away from is Yooji's!