Synopsis
Ordinary high school student Kyou Sogoru is passionate about swimming and lives in scenic Maihama City. His days are filled with time with friends, swimming, and video games. But his routine is shattered when a lovely and enigmatic girl named Shizuno Misaki makes an unusual proposal—jump into the school pool with her. That pivotal jump transports Kyou to a devastated world where humans pilot humanoid fighting machines called Zegas to battle hostile aliens known as Gards-Orm. To lead this effort, humans have formed Cerebrum, a resistance group working to stop the Gards-Orm from wiping out humankind. As Kyou engages in battle missions, comes to know his fellow Zega pilots, and sees many deaths, he starts to doubt the actual nature of this reality and his own existence.