In a small bowl, combine miso, sugar, sake and mirin.
In a shallow container, combine the marinade and salmon. Marinate at least 30 minutes in the fridge.
Heat the pan over medium low heat. place a parchment paper in a pan. Place salmon on top of the parchment paper so salmon doesn’t burn. Cook 6-7 minutes both side or salmon gets the nice grill mark and color becomes opaque.