1. Prepare the sauces: In a bowl, mix the soy sauce, teriyaki or mirin, and a pinch of pepper. Set aside.
2. Heat butter or sesame oil in a skillet over medium-high heat. Add minced garlic and ginger, and sauté until fragrant.
3. Season the chicken pieces with salt and pepper, then add them to the skillet. Sear until browned.
4. Pour the prepared sauce over the chicken, stirring to coat each piece. Allow the sauce to thicken slightly and the chicken to develop a light char.
5. Drizzle with sesame oil before removing from heat. Serve with hibachi rice, noodles, or sautéed vegetables.

For Yum-Yum Sauce:
1. Combine mayonnaise, melted butter, Sriracha or ketchup, paprika, garlic powder, onion powder, cayenne pepper, sugar, and mirin if using. Add water to reach desired consistency.
2. Serve alongside the chicken as a dipping sauce.