Amano Yukiteru, a second-year middle school student, is a boy who struggles to make friends. He views himself as a bystander and constantly records everything he sees in a cell phone diary. Tormented by his solitude, Yukiteru began to imagine things such as a friend named Deus Ex Machina, who appears to be the Lord of Time and Space. Observing Yukiteru's miserable state, Deus grants him a new ability: his diary will now record events that will occur in the near future. Yukiteru is then compelled to participate in a game, the winner of which will become Deus' successor.