Saw these Japanese sausages and there were three interesting flavours:
Fish sausage with Salmon
Fish sausage with cod fish roe
Fish sausage with sea urchin
[note that the labelling is grammatically wrong, the above was my interpretation, see the pictures for the real name, infact quite alot of the English on the label did'nt make sense such as keep away from sunbeam and out of frame!]
I tried to go to their website but it just got redirected to some site in China and the labelling mistakes seems more Chinglish than Japanese-English.
The one that tasted the best was filled with sea urchin, but of course don't expect real sea urchin.
The one shown on the picture was the cod fish roe because I thought the cod roe looked interesting!