Preheat the oven to 375°F and line a baking sheet with parchment paper.
In a mixing bowl, combine the ground beef, ½ cup teriyaki sauce, drained pineapple, egg, onion, garlic, salt, and pepper. Mix until evenly blended.
Divide the mixture into four equal portions and shape each into a small loaf. Place the loaves on the prepared baking sheet.
Bake for 25 minutes.
Remove the pan from the oven and brush the tops of the loaves with the remaining ¼ cup teriyaki sauce. Sprinkle with sesame seeds.
Return to the oven and bake for 5 to 10 more minutes until the internal temperature reaches 160°F.