Yukiteru, Yuno, and Kurusu band together to prevent the battle of Future Diaries from getting out of hand. But when Yukiteru discovers a dark secret about Yuno that changes everything, will he still be able to trust her?

Now wary of his new "friends," Yukiteru joins them on an investigation of a priestess from a temple who seems to have mysterious powers. As new Diary owners show up, each with their own ambitions, who, in this dark and desolate world, is friend and who is foe?