Seonyu Udon is an udon restaurant in the Seonyudo area that also serves tonkatsu. The shrimp tempura udon comes with well-fried shrimp on top, and the mazesoba is mixed with kelp vinegar before eating. A wait forms even if you arrive only a little late, and the bukkake udon tastes like soba. The udon broth and seasoning are on the light side.