A teenager wakes up on a hillside with no memory except this: he can kill aliens. The world doesn't need him to understand why. It needs him to fight, and the three people learning to live with him need him to stay, and those two things are never the same thing. The animation pulls back and lets silence do the work, trusting you to feel the weight of a boy who exists only because he's useful, learning what it costs to be loved anyway.
An alien invasion pushes humanity to the brink of extinction until Arikawa finds Kakashi, a mysterious teenager with an impossible gift: the ability to single-handedly obliterate the invaders. There's just one problem. Kakashi has no memory of who he is or how to access the power coursing through him. Desperate to save the world, Arikawa brings Kakashi into his home, where he and his commanding officer Shiro attempt to unlock the teenager's dormant abilities. What starts as a practical solution spirals into something far more complicated. As Kakashi begins to recover fragments of his past, unexpected emotional currents emerge between the three of them. Personal desire clashes against the survival of an entire species, and Kakashi's growing uncertainty about his own purpose threatens to unravel the very plan meant to save them all. This OVA balances high-stakes sci-fi action with intimate character tension, asking whether humanity's savior will choose to fight for a world that might not deserve saving.