Prepare the mixture
In a bowl, combine ground chicken, green onions, soy sauce, sake, ginger, egg, breadcrumbs, and sesame oil. Mix until smooth and slightly sticky.Shape the meatballs
Lightly wet your hands and form small oval or round meatballs. For a traditional look, shape them onto skewers. Cook the meatballs
Grill over medium heat, turning occasionally, until fully cooked and lightly browned.Alternatively, cook in a pan over medium heat until golden on all sides. Prepare the glaze
In a small saucepan, combine soy sauce, mirin, sugar, and sake. Simmer until slightly thickened.Glaze and caramelize
Brush the sauce over the meatballs during the last minutes of cooking. Turn them to coat evenly and allow the glaze to caramelize.Add sesame topping
Sprinkle toasted sesame seeds over the hot meatballs just before serving. This adds a nutty flavor and a slight crunch.