Place cutlets, one at a time, in a heavy-duty zipper-lock bag and pound gently to ¼-inch thickness using a meat pounder or the bottom of a heavy 8-inch skillet. Season generously with salt and pepper.

If using slices of fresh Japanese milk bread: Trim crust from milk bread; discard trimmings. Cut trimmed bread lengthwise into 1 ½-inch-thick batons. Using a food processor fitted with the grater attachment, process bread into coarse flakes.

Fill 3 wide, shallow bowls or high-rimmed plates with flour, beaten eggs, and panko, respectively. Dredge each cutlet in flour, then coat with egg, and finally press into breadcrumbs. Transfer to a clean plate and repeat with remaining meat.

Fill a large skillet with ⅓ inch oil and heat until shimmering and just shy of smoking, about 350°F (175°C).

Gently lower cutlets into hot fat, frying in batches if necessary. Fry until golden brown and cooked through, about 3-5 minutes total. Transfer to paper towels to drain and season with salt.

Slice tonkatsu into thin strips and serve immediately with shredded cabbage, lemon wedges, white rice, Japanese pickles, and tonkatsu sauce.