Prepare the marinade by combining the ingredients listed in a bowl and place in the refrigerator.
Make the Menchi Katsu mixture. In a large bowl, mix together the binder mixture ingredients listed under to soften the oatmeal and breadcrumbs. Add ground pork and chopped edamame, knead well, and shape into patties about 1.5cm (0.6in) thick.
Dredge the patties in the following order: cake flour, beaten eggs, and panko breadcrumbs.
Heat frying oil to 170°C (~335°F), fry the patties for 4-5 minutes or until cooked thoroughly, then drain excess oil. Serve on a plate, accompanied by the marinade, olives, and wholegrain mustard