Shinji Ikari attends the NERV Foundation Academy and lives a life of relative normality. One night he encounters Rei Ayanami and Kaworu Nagisa fleeing the scene of a violent explosion and is eventually recruited to assist them and Asuka Sohryuu Langely in fighting the Angels, who have taken on human form, in order to retrieve their cores to support the world tree, Yggdrasil. Should the Yggdrasil die, their world would be thrown into a chaotic state where parallel streams of existence collide, eventually bringing about the destruction of all things.