The artificial sun that lights the frozen planet La Metalle is dying, threatening to extinguish what little life is left there. Queen La Andromeda Prometheum decides that the only way for her people to survive is for them to submit to Hardgear's transformation process, which will turn everyone's body into machines. The Queen's daughters, Emeraldas and Maetel, refuse to submit to this process, and fight to stay human.

The social and political reforms implemented by Reinhard are finding growing consensus among the citizens of the Galactic Empire. Meanwhile, the Free Planets Alliance is experiencing a declining phase, its national power weakened significantly due to widespread government corruption, despite military success has been achieved on the battlefields. As the balance of power between the two super states dominating the Galaxy is clearly undergoing a major shift, Adrian Rubinsky, the Landesherr of the autonomous and nominally neutral dominion of Fezzan, sees an opportunity to take advantage from the situation.

Masahiro Setagawa is a hopeless teenager who is often used by the neighborhood bullies as an errand boy. Defenseless, Masahiro knows that nobody will ever save him. However, his life drastically changes when he meets Kousuke Ooshiba, a man known as the "Bear Killer," who takes down neighborhood gangs. A year later, Masahiro and his former friend, Kensuke Ooshiba, attend high school, only to find that Kousuke is their math teacher. While the three grow closer, Masahiro starts to view Kousuke as his "hero," and Kousuke develops an urging desire to protect Masahiro. However, their normal lives take a turn when Kensuke's childhood friend, Asaya Hasekura, returns, seeing Kensuke as more than just a friend, much to his surprise. Will the three boys be able to live a regular high school life? Or will forbidden love keep them apart forever?

Second season of Muhyo to Rouji no Mahouritsu Soudan Jimusho.