In the year 2050, a new craze sweeps the world by storm. LBX - Little Battles eXperience. Collecting model robots may have just been a mere hobby, but LBX has changed that. Now, these robots fight each other in a competition to determine who is the strongest!Yamano Ban is one of the many youths enamored with LBX. However, due to his mother's disapproval, he has never tried his hand at it. One day, a girl whom he had never met before hands him an attache case. She quickly leaves the scene, leaving Yamano with these cryptic words: "Within this lies both humanity's hope and despair."