Yukiteru Amano, a shy middle schooler, keeps a digital diary of his daily life on his phone. One day, he discovers that his phone shows future events, which soon come true. After meeting his classmate Yuno Gasai, who has a similar "Future Diary," they learn that they, along with 10 other participants, have been chosen for a deadly survival game. The winner will become the successor to Deus Ex Machina, the god of time and space. Yukiteru and Yuno must navigate this brutal battle royale, using their diaries to outsmart their competitors and survive.