The year is 25XX.
The world has grown uninhabitable, forcing humanity to live in isolated colonies. Yuuki, an ordinary student, resents the monotonous life she leads at school.
Rumors abound of a group of superheroes who fight monsters called Vectors, but these tales aren’t enough to stir her heart. The popular boys at the academy hold little interest for her as well.
One night, Yuuki sneaks out of her dorm and comes face-to-face with one of the beasts. Just when it seems her life will be forfeit, four girls wielding mysterious powers suddenly appear and swiftly take down the Vector.
In the wake of that shocking incident, Yuuki joins the ranks of those heroes and begins living the exciting life she craved. On top of that, the popular boys at school keep popping up for some reason too…
What secrets are they hiding? And who exactly is the enemy?
