In a medium bowl, whisk together the soy sauce, rice vinegar, honey, brown sugar, minced garlic, and freshly grated ginger until smooth and well combined.

Place the chicken thighs in your slow cooker, ensuring they are evenly spread out for uniform cooking. Pour the homemade teriyaki sauce over the chicken.

Cover the slow cooker with its lid and set it to cook on high for 2 hours or low for 4 hours.

Once cooked, carefully remove the chicken thighs from the slow cooker and shred the chicken into bite-sized pieces.

Prepare a cornstarch slurry by mixing cornstarch with water until smooth. Strain the cooking liquid from the slow cooker into a saucepan.

Stir in a drizzle of sesame oil into the thickened sauce and toss the shredded chicken back into the saucepan.

Spoon over warm cooked brown rice and garnish with sliced green onions and sesame seeds.