Soak some bamboo skewers in water for 30 minutes, and cook White Rice (to taste) according to package's instructions.
Combine Soy Sauce (1/2 cup), Mirin (50 milliliter), Sake (80 milliliter), Granulated Sugar (70 gram), and Scallion (1 bunch) in a sauce pan. Simmer for about 15 minutes until the Yakitori sauce becomes thick and set aside.
Use kitchen towel or paper towel to dry the Boneless, Skinless Chicken Thigh (500 gram), and dice it into cubes.
Cut the green part of Scallion (9) into the same length as the chicken.
Arrange the chicken and scallions alternatively and pierce through with the skewer. Repeat until all the ingredients are finished.
Preheat a pan and coat with a thin layer of Vegetable Oil (to taste). Pan fry the skewers for 5 minutes on each side until golden brown. Once the skewer is cooked, brush the Yakitori sauce on top until it is completely covers the skewers.
Arrange three skewers on top of a bowl of freshly cooked rice and serve immediately. Bon Appetite.