Sear thighs skin-side down until lightly browned, 4–5 minutes. Flip and cook 2 minutes. Remove briefly.
Whisk soy sauce, 1 cup water, pineapple juice, brown sugar, garlic, ginger, vinegar, sesame oil, pepper, and flakes.
Nestle chicken into the sauce, skin-side up. Bring to a lively simmer.
Cover and simmer gently for 20 minutes.
Uncover, flip chicken, and cook until tender, 10–15 minutes more.
Transfer chicken to a plate. Boil sauce 5–8 minutes to reduce slightly.
If thicker glaze is desired, stir in cornstarch slurry and simmer 1–2 minutes.
Return chicken to the pot and spoon glaze over. Top with green onions and sesame seeds.
Notes
For a richer flavor, swap pineapple juice with 1/4 cup mirin and add 1/4 cup extra water. Want crisper skin? Broil the cooked thighs on a rack for 2–3 minutes, then glaze. Leftovers keep 3–4 days refrigerated; reheat gently with a splash of water.This recipe is an original creation inspired by classic Easy Hawaiian Shoyu Chicken Recipe flavors. All ingredient ratios and instructions are independently developed.