Rika Furude and Satoko Houjou are best friends who have lived in the small village of Hinamizawa for their entire lives. Alongside their other friends, they spend every day together, and every moment is filled with fun and laughter. However, as Rika and Satoko begin to grow older, a life-changing opportunity presents itself to both of them. Rika is determined to follow her dreams and wants Satoko by her side. Although Satoko is hesitant, she decides to walk this path with Rika. However, the realization of her dream forms a rift between them. This leaves the girls living in completely different worlds, with Rika enjoying her new life and making new friends while Satoko grows more and more isolated. Longing to return to the nostalgic days in Hinamizawa, Satoko despairs and wishes things could be changed. Just when she is at wits' end, an encounter with a supernatural entity changes Satoko's perception and imparts new revelations about her best friend Rika. This begins her journey to get the future she desires—by any means necessary.

The misadventures of Issei Hyoudou, high school pervert and aspiring Harem King, continue on in High School DxD New. As the members of the Occult Research Club carry out their regular activities, it becomes increasingly obvious that there is something wrong with their Knight, the usually composed and alert Yuuto Kiba. Soon, Issei learns of Kiba's dark, bloody past and its connection to the mysterious Holy Swords. Once the subject of a cruel experiment, Kiba now seeks revenge on all those who wronged him. With the return of an old enemy, as well as the appearance of two new, Holy Sword-wielding beauties, it isn't long before Issei and his Devil comrades are plunged into a twisted plot once more.

The year is 1996, and second-year high school students Haruo Yaguchi, Akira Oono, and Koharu Hidaka live their lives as passionately about video games as they were five years ago. Brought together by arcade games, what began as a healthy rivalry and friendship has turned into something more. As they endeavour towards understanding their unfamiliar feelings, they work with allies, navigate high school, and find that, although life has its many challenges, there's always a game or two they can rely on.

Rika Furude and her group of friends live in the small mountain village of Hinamizawa; in June 1983, they welcome transfer student Keiichi Maebara into their ranks, making him the only boy in their group. After school, they have fun playing games and spending each day living their lives to the fullest. Despite this seemingly normal routine, Keiichi begins noticing strange behavior from his friends, who seem to be hiding the town's dark secrets from him. Elsewhere, a certain person watches these increasingly unsettling events unfold and remembers all the times that this, and other similar stories, have played out. Using that knowledge, this person decides to fix these broken worlds. However, when certain variables change, the individual is faced with a horrifying realization: they have no idea what to expect or how to stop the impending tragedy.