Hi! To my knowledge there are two strong options. Sheffield Knife Sharpening in the UK IG: sheffield_knive_sharpening or Shinogi Sliperi in Sweden IG: shinogi_sliperi. I'm sure there are more local options, but both these will do an excellent job with your yanagiba honyaki.
Tight for cash due to a few customs coming. Fantastic cutter, nice size. D-shaped handle in african blackwood with "rattan". It has only been sharpened once, but I have given it a mirror finish using fine sandpaper and diamond compound. Has some patina as shown in the pictures.
Evan...