Description: In the future, man will travel through space like never before... on trains! The trains of the Galaxy Railways transport countless galactic citizens from one planet to the next. But the Galaxy Railway fleet is under constant threat from terrorists, meteor storms, and malicious alien life. Enter the SDF, the elite force protecting the Railways Fleet. Follow the exploits of Manabu Yuuki, a young man following his destiny, as he joins the Space Defense Force and is assigned to Sirius Platoon to protect the safety of the Galaxy Railways.