Super Robot Taisen BX combines stories from various anime series, but it features a central plot that links the characters and robots from different series together as they fight against enemies from other dimensions. The story begins when Earth is attacked by Argon, an enemy from another dimension with a plan to destroy the world. Argon enters the human world through a dimensional portal and reveals a powerful enemy, causing the Earth to face an unprecedented threat. Meanwhile, a group of heroes from various robot series are drawn into this event, including characters from Mazinger Z, Gurren Lagann, Code Geass, Aquarion, Dancouga, and many other series that players will encounter throughout the game. The coming together of these robot heroes from different dimensions leads to cooperation between the various groups, each with their own unique fighting methods and philosophies. In the end, they must all work together to battle against the enemies that aim to destroy the world.