Nathaniel Crest is a normal 15 year old guy, who plays bakugan. He came to Japan in order to study there. One day, his life changes. He meets a bakugan, a special one. Leonidas. Not everyone seems to trust him at first sight, but Nathaniel does. At the same time, darkness is rising. Some evil bakugan called Vladitor wants to dominate over all bakugan. Together with Leonidas, Nathaniel faces different opponents and challenges. Will they be able to defeat Vladitor?