• Gather all the ingredients.
  
• From 1 lb boneless, skin-on chicken thighs, cut each chicken thigh into 2 pieces (as you see, this chicken thigh is large). Cut off any excess fat. Prick the skin with the tip of the knife to help distribute the flavors and heat faster.
  
• Lightly sprinkle both sides with ¼ tsp Diamond Crystal kosher salt and ⅛ tsp freshly ground black pepper.
  
• Combine the sauce ingredients in a small bowl: 2½ Tbsp soy sauce, 2 Tbsp sake, 1 Tbsp mirin, and 1 Tbsp sugar. Whisk until the sugar is dissolved. Set aside.
  

To Cook the Chicken

• Heat a large frying pan over medium heat. When it‘s hot, add 1 Tbsp neutral oil and distribute it evenly. Add the chicken, skin side down, to the hot pan. (If you‘re doubling the recipe, fry the chicken in batches and return it to the pan before continuing to the next section.)
  
• Cook the chicken until golden brown, roughly 4–5 minutes.
  
• When the bottom side is nicely brown and crisp, flip over and cook the other side for 3 minutes.
  

To Steam and Add the Sauce

• Add 4 Tbsp sake and cook, covered, until cooking liquid is gone.
  
• Remove the lid and wipe off any excess oil from the frying pan with a paper towel.
  
• Add the sauce ingredients and 1 Tbsp unsalted butter.
  
• Coat the chicken well with the sauce. Spoon it over the chicken a few times.
  
• Serve the chicken onto a plate and drizzle it with some sauce. I usually serve simple veggies like blanched broccoli and tomatoes (serve with homemade Wafu Dressing or Sesame Dressing).
  

To Store

• You can keep the leftovers in an airtight container and store in the refrigerator for up to 3 days and in the freezer for a month.