The UMAMI WAGYU burger, listed under Banzai Bites at Katsu Burger, is built from a wagyu beef patty topped with Swiss cheese, bacon, caramelized onions, creamy Japanese mayo, and tonkatsu sauce in slider form.[10] This variation stands out because it brings Wagyu richness into a compact burger while layering it with sweet onions and a savory-sweet Japanese sauce profile rather than standard American toppings.[10] Eating it, you get a crisp sear on the small patty, a juicy interior, and a mix of smoky bacon and tangy sauce that makes each bite feel dense with flavor despite the smaller size.[10] Menu descriptions and diner commentary note that it’s a more indulgent option among the bite-sized offerings, giving you a Wagyu experience without committing to a full-size burger.[10]