Make salt water (mix 1 litter or 4 cups of water plus 1 tsp salt, not in the ingredients above). Wash oysters in salt water. Drain cloudy water and pat dry well with paper towels. Salt and pepper lightly.
Coat the oysters lightly with flour, dip in egg, then cover with bread crumbs. Handle gently so that the oysters don't get squashed.
Heat deep frying oil to 350 F, and deep fry the crumb-covered oysters. You can check the temperature by dropping a bread crumb in the oil. If it comes up to the oil surface right after it's dropped in, the oil is ready.
Fry until the color turns golden brown and the oysters float in the oil, about 3 minutes, turning a couple times as they cook.
Serve with Tonkatsu Sauce and lemon if you want.