Crumble ground beef into a skillet over medium heat. Stir garlic, oregano, chili powder, and basil into the beef; cook and stir until beef is completely browned, 7 to 10 minutes.
Combine light red kidney beans, dark red kidney beans, diced tomatoes, and corn in crock of a slow cooker. Stir cooked ground beef into the bean mixture.
Cook on Medium-Low for 2 hours. Stir sugar into the chili and continue cooking as long as you can wait, at least 6 hours. Season with salt and black pepper to serve.
