In the near future, the automobile company JHC Motors has built Watch Cars, small sentient robot cars meant to be friends to kids and grown-ups alike, and they have caught on around the world. Owners and their Watch Cars face off in a competitive Battle League. Jino, a young Watch Car Master, enters the league with his own car, Blue-will. When an evil group called the Rangers of Darkness moves to take over every Watch Car in the city, Jino and his friends set out to stop them. The result is an action series built on robot car battles.