Mysterious creatures have been terrorizing an island, forcing locals to flee their once-thriving home. With government funds lacking for monster eradication, Tajima purchases the only construction company left and transforms it for the task. Thankfully, the brilliant Testuro Okino and his new robot, Bullbuster, come to their aid. But the team is on a tight budget. Can they save the island?

Eiichirō Maruo (nicknamed "Ei-chan" for his grades being straight "A") is an honor student, bookworm, and is not interested in anything other than studying. In order to solve his problem of lacking physical strength, he enrolled a tennis school and soon found the fascinating side of tennis. Being a tennis newbie lacking physical strength, he supplement his shortcomings with his excellent observing and analyzing skills.

Giant Killing follows a ragtag bunch from East Tokyo who are struggling in Japan's top football league. Nearing the bottom, they have lost 5 matches in a row which hasn't done much to team morale. Even with the fan's turning their backs on the team, it seems as if the end is near. East Tokyo United can only blame their coach right now. However, their Coach is going to do something drastic to prove to his team and fans, that against the biggest club in the nation, he can make this team win...