Mix together the soy sauce, garlic, ginger, sugar, sake and sesame oil in a
glass baking dish or plastic storage container. Put the pork in the dish and
turn to coat with marinade on all sides. Let marinate for at least 1 hour or,
for best results, cover and refrigerate overnight.
Preheat the oven to 425 degrees. Remove the pork from the marinade and place in
a roasting pan. Roast, basting every 15 minutes, until the internal temperature
reaches 150 degrees on an instant-read thermometer (inserted in the thickest
part of the meat).
Remove from the oven and let cool to room temperature before slicing.