Years ago, the opening of an interdimensional portal released two beasts into the skies over the Sea of Japan, visible to all the countries along the coast. After destroying the naval patrol sent to investigate the disturbance, the two beasts then turned against each other. Witnessing the fight from Japan, scientists Joe and Marie Hayakawa were sucked into the rift. Upon returning to Earth, they compiled and published the academic findings from their voyage in a legendary book titled ''Day of Succession''. Attempting a second expedition to that other dimension twelve years later, the couple have not returned. Twins Ai and Yu Hayakawa decide to set forth in search of their parents and the mysterious Wonderland they studied. In the ruins of an abandoned subway station, the two wait for a train to take them to the world beyond. On board they meet Lisa Pacifist, who quickly decides to aid the two in the search for their missing family. Can the three of them manage to find Joe and Marie?

It's summer vacation in Penguin Village, and a very pretty vampire pays them a visit! (Source: BakaBT)

At the Penguin Village, the dinosaurs styled monster named Dodongadon appeared. But he was small as Arale and did not have strong power. Arale defeat him very easily, and Dodongadon called his mother Mamangadon. She was huge and had a big power. How Arale can defeat this big monster? (Source: Official Website)

Bakugan Interspace is a virtual reality system, where players can brawl against each other and take part in tournaments. Initially designed to help practice and enhance Bakugan skills, it quickly became a meeting place for many enthusiasts. During one of Danma Kuusou's duels, the Interspace crashes, and he gets knocked out cold. Before regaining consciousness, he experiences a vision of Bakugan at war with each other once again. The explosion of energy that accompanied Danma's fight and caused the shutdown of the system sends shock waves across the galaxy, attracting the attention of the Twelve Orders, a Gundalian organization. They infiltrate Bakugan Interspace, looking for strong brawlers to join them in their upcoming war with another alien race, the Neathians. Danma and his companions—Shun Kazami and Chouji Marukura—soon find themselves caught up in an extraterrestrial war. However, distant as it may seem, the conflict threatens the very sovereignty of Earth and the future of the Bakugan race as well. [Written by MAL Rewrite]