In 2046, a revolutionary 80% shock-absorbing reinforced cardboard has been developed, rapidly transforming the world's exports. The reinforced cardboard would soon become the battleground for a popular children's hobby called "LBX" (Little Battler eXperience).

Four years later, a boy named Yamano Ban who loves to play with LBX (although without a mecha himself) is given a case containing the model AX-00 by a mysterious woman. He is told that he now holds the hopes and despairs of mankind in his hands.

[Source: MyAnimeList]

One year after the fight with the Innovators, a new terrorist organization called the Detectors threatens the world using LBXs. Ban joins up with new and old friends to stop the Detectors.

[Source: Anime News Network]

As Shinsei Inazuma Japan was about to have a match with Inazuma Legend Japan, a mysterious attack of a person and a swarm of robots interrupted, and another mysterious girl's power drove the world into another dimension. As the world of Inazuma Eleven Go and Danball Senki W met, the two teams must work together to find out what happened to their worlds.

[Source: Wikipedia]

Year 2055, 4 years after the events in Danball Senki W. LBXs have become the world’s largest hobby, big enough for pro leagues to be established, and people to make their entire living off being an LBX player. 14-year-old Arata is a new transfer student at Kamui Daimon Integrated Academy on Kamui Island, near Japan. Known to be the most prestigious institution in the world for raising LBX players and mechanics, entrance to the academy requires an extremely competitive hurdle of being the champion of at least 3 official tournaments. Along with other members of his platoon, they face rivals and delve into the secrets lurking within the academy.

[Source: Anime News Network]

Arata Sena is unable to leave the island after he forgets to have his permission form signed. However, he gets an even better opportunity: facing off against LBX legend Ban Yamano.