Shrimp and Crab Are Everywhere

ANSWER

For a crustacean allergy specifically, Japan can be trickier than it first appears, because shrimp and crab don't stay confined to obviously seafood-labeled dishes. They show up in some dashi and soup bases, in processed fish cakes like kamaboko and chikuwa (which are common additions to soups, hot pot, and bento boxes), and even in savory snack foods where shrimp powder or extract is used purely as a flavor booster. The pattern to watch for is exactly this: shellfish hiding inside something that reads as "not seafood" at all, rather than showing up as a recognizable shrimp or crab on the plate. As with other allergies, packaged snack labeling is more reliable than restaurant menus, and it's worth specifically asking about kamaboko/chikuwa-style fish cake and dashi when eating out, since those are the two most common hidden sources.