Takeru Hinata's past is shrouded in mystery. A once typical high school student, he finds himself spiraling down the cruel path called destiny laid before him due to his family's name. As the deeply philosophical plot thickens it's made apparent that his tyrannous, sexually abusive father, is forcing him to don the "MARS" (a special, anti monster, armored suit) to protect the citizenry of Japan alongside the Anti-unidentified Ancients Special Team (AAST) from the mysterious monsters called "Ancients".

Some time after a space mission to Mars ends in destruction, strange monsters called "Ancients" begin appearing around Tokyo. A group of specialists consisting of three girls and one troubled young boy must fight the Ancients until they can come to understand exactly what it is they are fighting. When one of the Ancients tells them that they are the true invaders of Earth, they must search within themselves to grasp what truly is reality. <br><br>
(Source: Anime News Network)