I bought several rods of them at Ito-Yokado. It cost 88 yen ($0.95 €0.74) per one skewer. It is a common side dish when people drink alcohol and it is seasoned with bittersweet sauce (soy sauce and sugar). We also have salty version of yakitori. Bittersweet yakitori is brown, and salty yakitori is white.
The followings are types of yakitori. All of them are bittersweet yakitoris.
Chicken thigh with leeks