Locals use wasabi with sashimi because its pungent and spicy flavor enhances the delicate taste of raw fish, providing a refreshing kick and balancing the richness of the fish. It also has antibacterial properties which help reduce the risk of foodborne illnesses associated with consuming raw seafood. Additionally, the strong aroma and sinus-clearing properties of horseradish create a sensory experience, temporarily opening nasal passages and adding to the enjoyment of the meal.