The series is set in the near future. The automobile company named JHC Motors has created the Watch Cars, which are miniature sentient robotic cars that have become good companions to children and adults alike. Ever since, Watch Cars have become a global trend. The Watch Car Battle League is a competition where Watch Cars battle alongside their trainers. Jino, one of the young Watch Car Masters, goes to the Watch Car Battle League with his Watch Car Blue-will, but The Rangers of Darkness, an evil force plan to takeover all the Watch Cars in the city. Jino and his friends Roy, Maru and Ari, along with their Watch Cars, must stop them.