Future Diary Redial

 Redial is a manga and OVA that acts as a conclusion to the Future Diary series. It was first announced in a 2012 advertisement and the first chapter was released in early April 2013. It includes a new Future Diary manga volume and an original anime DVD, with the latter running at about 25 minutes long.

Plot
Redial follows the Yuno Gasai (Yandere) of the Third World, who is far happier and more stable than her First World counterpart. Thanks to the Second World's Yukiteru Amano, the Gasai family was able to mend its dysfunctions, allowing Yuno to live a normal life. However, she is haunted by images, feelings, and moments of déjà vu that make her feel like she's missing something - or rather, someone - very important.

The first half of the OVA is used to show what has become of the diary holders in the Third World where the future diary death game never took place. These are generally short, comedic scenes that take place as Yuno and her classmates—the non-diary holder supporting cast of the series—take a school trip to the beach. These scenes do little to add to or take away from the series and are just there for laughs. However, occasionally we get to see something involving Yuno, hinting at the inner turmoil that is taking hold of her—such as the fact that she keeps a phone diary with nothing but time stamps at 10-minute intervals.

The second half focuses almost exclusively on Yuno as midnight of July 28th approaches and she begins to converse with a voice inside her head about the upcoming end of the world and the person she can't remember. She ends up going to Deus's realm, guided by the mysterious voice; Third World Muru Muru tries to stop her, but is foiled by Minene Uryuu. Yuno is briefly confronted by Aru Akise, who tells her that another her murdered a lot of people and was selfish towards the one she loved. She is also able to get past him, and meets the Murmur of the First World, who tearfully gives her the First Yuno's memories. Due to this, the First Yuno is revived and transferred into the body of the Third Yuno.

Shortly after, we are shown Yuuki, who for 10,000 years, has only mourned the death of Yuno. Finally, his future diary begins to rewrite itself saying that, "Yuno came to visit." After he reads this, Yuno breaks through the walls separating the two worlds, and jumps into an ecstatic Yuuki's arms. It is here that she asks him to go stargazing with her like they had promised.