Combine all the ingredients up to the pork loin in a bowl and mix together. Place the pork loin in the bowl, and rub the mixture into it. Set the pork in the bowl of a slow cooker and pour the sake over it. Close the lid and cook on low 6-8 hours, until the pork is cooked and shreds easily. Pull the pork apart and drain the liquid. Store in the fridge and use within 3-4 days.