Step 1

Put mirin, soy sauce, sugar and garlic, if using, into a medium-sized sauce pan, and cook over medium heat until there is only half as much sauce remaining.

Step 2

Let cool slightly while you are preparing the chicken.

Step 3

Cut chicken into bite-sized pieces; keeping the skin on is usual in Japan.

Step 4

Thread chicken onto skewers, alternating with green onion if desired.

Step 5

Begin grilling the chicken skewers on both sides without the sauce, when the meat starts changing color, brush the sauce on both sides, and continue grilling, brushing on sauce about 3 times total, and turning until done.