Based on the Japanese novel by Hiroshi Sakurazaka, the story is officially described as follows:
There's one thing worse than dying. It's coming back to do it again and again... When the alien Gitai invade, Keiji Kiriya is just one of many raw recruits shoved into a suit of battle armor and sent out to kill. Keiji dies on the battlefield, only to find himself reborn each morning to fight and die again and again. On the 158th iteration though, he sees something different, something out of place: the female soldier known as the B*tch of War. Is the B*tch the key to Keiji's escape, or to his final death?
Whether or not Pitt takes the roles remains to be seen, but Warner Bros. is expected to move on the project immediately, taking advantage of the just-cancelled Liman project, Luna.