Mix brown sugar, soy sauce, water, rice vinegar, garlic, ginger and sesame oil in a small bowl.
Place chicken in slow cooker. Pour sauce over chicken.Cook on HIGH 4-5 hours or LOW 6-8 hours.
Remove chicken and shred.
Pour sauce into a and bring to a boil. Stir water and corn starch together to create a slurry. Pour into sauce and whisk until it begins to thicken. Remove from heat.
Add shredded chicken back to slow cooker and pour sauce over chicken. Stir.Serve over rice.