Cut boneless, skinless chicken thighs into bite-sized pieces and trim off any excess fat.
Add chicken to a bowl and combine with Kewpie mayonnaise, soy sauce, mirin, garlic powder, ginger powder, salt, black pepper, and cornstarch.
Mix until all pieces are evenly coated. Cover and refrigerate for at least 30 minutes and up to 24 hours.
Heat a pan over medium-high heat with a few tablespoons of oil. Add chicken in an even layer without overcrowding. Cook for 6 to 7 minutes, turning as needed, until golden brown, crispy, and fully cooked through.
Serve over hot white jasmine rice. Garnish with green onions, black pepper, and a lime wedge. Enjoy!
