One of the most well known mecha from the Super Robot Taisen series, the Psybuster is back in the game's Nintendo DS remake. Ra Gias is a world that exists underground. Although their science and technology is far more advanced than any kingdom on above earth, this land is prophesied to fall under an unidentified force.
To counter this unknown power, the king order the alchemists to create weapons for defense. After years of research and development, the alchemists create the Masou Kijin, mecha of massive power. However, the power is so great that these weapons won't obey the commands of normal pilots.
Just when everybody lost hope, Andou Masaki, a spirited teenager appeared. With the Masou Kijin at his side, the boy embarks on a journey to become the savior.