The story of Iron Knight revolves around the life of Teppei Ushizume. Teppei is a normal boy that lives a normal life. He goes to school, and has friends like every other 10-year-old boy. Although he doesn't live with his parents, because his mother died and his father has to be away from home for long periods of time because of his job, he stays with Tsubasa Himegami, a very close friend of his, and her family until his father returns. But everything changed when the Goblins rose and the Era of Chaos began. Teppei discovers he's a Goblin too and uses his newly found power to fight the goblins. He vowed to fight until he can save the city, and his friends and family.