Tsukune - Japanese chicken meatballs

Another meatball I had made for the bridal shower was  Tuskune, Japanese Chicken Meatballs,  modified recipe of Just One Cookbook.  

Nami talks about using eggs or bread crumbs to bind the meat, but also her Mom's trick to knead the chicken to prevent it falling of the skewers.  

I was interested to know if kneading the mixture and also per-cooking a third of the ground chicken would help in forming the meatballs as in using Maple Leaf ground chicken or turkey, the mixture is sticky and difficult to form into meatballs. 

The meatballs were mixed with 2 T of sesame seed oil, minced onion and baste with Yakitori Tare when grilled.  The homemade Yakitori sauce that Just One Cookbook posted is below.

Yakitori Sauce (Tare) 

• ½ cup soy sauce
• ½ cup mirin
• ¼ cup sake
• ¼ cup water
• 2 tsp. packed brown sugar