Fried shrimp & Tartar sauce koppepan boy Koppepan is a piece of bread that looks like a large hot dog bun that sometimes has cream or jam inside. It's a common bread in Japan. Fried shrimp & Tartar sauce koppepan is made by sandwiching fried shrimp in bread and sprinkling it with tartar sauce. Fried shrimp is a dish that originated in Japan and is fried shrimp in a large amount of cooking oil.