Season the pork with salt. Mix the rice wine and 1 teaspoon ginger and spread on the pork. Stack the pork and set aside.
Peel, quarter and seed the cucumbers; cut into 4-inch spears. Toss with the sugar and vinegar. Toast the pepper flakes with 1 tablespoon salt in a skillet over medium heat, about 4 minutes; set aside.
Beat the eggs with 1/2 cup water in a shallow bowl. Put the panko and cornstarch in 2 separate shallow bowls. Dredge each piece of pork in cornstarch, dip in egg, then coat with the panko. Heat 1/4 inch of peanut oil in a large skillet over high heat. Fry the pork in batches until golden, 3 to 4 minutes per side. Drain on a paper-towel-lined plate.
Sprinkle the cucumbers with some of the spiced salt. Mix the tonkatsu sauce and the remaining 1/2 teaspoon ginger in a bowl. Serve the pork with the cucumbers and sauce.