Heat oil in a large saute pan over medium-high heat. Dredge the geoduck scaloppine in the seasoned flour, quickly shaking off excess, and carefully placing them into hot oil. Add only as many as the pan will comfortably hold at one time. Allow to brown on first side, approximately 2 minutes, and then turn over gently with metal tongs. Cook for 1 1/2 to 2 minutes, then remove the scaloppine to a warm serving platter. Continue to do the same with all the pieces of geoduck. Set aside and keep warm (without cooking further).
Pour off any excess oil from the pan. Add the sake, aji-mirin, garlic, and ginger. Reduce over high heat until reduced by 75 percent, the liquid remaining in pan should become almost syrupy. Add the butter, remove from the heat, and swirl the softened butter into the liquid, forming an emulsion. Add lemon juice and blend thoroughly. Arrange the geoduck attractively and then evenly nap the sauce over the scalloppine. Sprinkle with cilantro and garnish with lemon wedges.