The Iron League: a place where teams of robots, under individual "owners", play various sports and duke it out in tournaments. Mach Windy is a member of Dark Prince, a team that doesn't play fair and fights dirty to win. Unsatisfied with the actions of his teammates, he defects against the will of Dark Prince's nefarious owner and joins Silver Prince: the weakest team in the league. Alongside faithful companions such as Magnum Ace and Bull Armor, Mach Windy and Silver Prince will battle against Dark Prince in games of soccer and baseball, and aim for the top!
Raimon Middle School's soccer club is led by the boisterous and determined Mamoru Endou. Armed with his grandfather’s notebook on special training and a fierce spirit, Mamoru desires to lead the team to victory, but there’s just one problem: the team is weak, unskilled, and disheartened. However, when several new members come on board, including soccer star Shuuya Gouenji from Kidokawa Seishuu Middle School, things begin to look up for the team. With ruthless opponents to defeat, special moves to acquire and the Soccer Frontier tournament to win, Mamoru and the gang will kick and block their way to victory!
Shippu and Inazuma Eleven are both sports anime that are clearly aimed at the kiddies. While it's true that Shippu is inhabited by mostly robots and Inazuma's cast is of the human variety, each has a very childish feel and will be aimed at the same audience.