You're not alone.
On any day, anywhere.Yta Hibiki, who is a first-year high school student living in Tsutsujidai, one day wakes up to find he has lost his memories.
And he meets the "Hyper Agent Gridman" on his old computerGridman says that Yta has a mission he must fulfill, and Yta sets out to find the meaning to those words and his memory loss.Yta's friends Sh Utsumi, Rikka Takarada, and Akane Shinj would always help him and spend their days with him.
But, their tranquil days are suddenly and easily crushed with the appearance of kaij.