Cut chicken to make an even thickness.
Poke skin with a fork.
Cover both sides with pinches of salt and pepper.
Place 1 tablespoon of potato starch into a plastic bag and add chicken.
Shake the bag to coat chicken in starch.
Place the chicken skin side down in a pan with no oil on medium heat.
When skin is golden brown, flip the chicken.
Cover and cook on low heat for 5 minutes.
While the chicken is cooking, combine 1.5 tablespoon of soy sauce, 1 tablespoon of sugar, 1 tablespoon of mirin, and 1.5 tablespoon of sake.
Remove excess oil in pan with a paper towel.
Add sauce mixture into the pan.
Cook on medium heat for 2 minutes.
Take chicken off heat and cut into strips.
Serve.