Preheat the oven to 375 degrees F (190 degrees C).
Place a saucepan over medium-high heat. Add pineapple juice, soy sauce, water, rice vinegar, cornstarch, ginger, and garlic; stir to combine. Bring to a boil and stir well. Reduce heat to medium and cook, stirring often, until sauce is reduced, about 5 minutes.
Place chicken thighs in an oven-safe casserole dish. Pour 1/2 of the teriyaki sauce over the chicken thighs.
Bake in the preheated oven for 30 minutes, basting thighs every 10 minutes with the remaining sauce. Garnish with sesame seeds.