In a mixing bowl, whisk together the soy sauce, rice vinegar, honey, brown sugar, minced garlic cloves, and grated ginger until well-blended.

Place the chicken thighs into the slow cooker and pour the homemade teriyaki sauce over the chicken.

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

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

In a small bowl, mix the cornstarch with cold water to create a slurry. Strain the cooking liquid into a saucepan, bring to a gentle simmer, and whisk in the cornstarch slurry.

Add sesame oil to the thickened sauce and return the shredded chicken back into the saucepan, stirring until coated.

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