A dimensional fissure occurred on the Earth suddenly, a bunch of mechanical beasts came to the Earth and attacked the city. Sean, who dreams of being a hero, accidently met with the mecha Skyden and they became partners during the attack. They worked together to fight against the enemy. After that, Mechanical beasts attacked the city every now and then. In the process of fighting against the enemy, Sean and Skyden became friends with warm-hearted Duncan, smart Thom and elegant Kay. They found out some relevance of the attackers and it seems that there is a more powerful leader behind them!