Shun Asanaga is a 15-year-old junior high school student with an optimistic and bright personality. One day, he finds a mysterious crystal in the office of his father, who is a scientist and businessman. When Shun touches it, the world becomes distorted, and he is sent into the world of Endra. Emilio, a prince of the kingdom of Endra, is nearing his 16th birthday and despises the reigning king, Delzain. Since Emilio is now at the age when he can inherit the throne, he takes up a weapon and attempts revenge. However, because Emilio is too weak, he is captured by Delzain and put in prison. When Emilio is in grief, the wall of his cell becomes distorted and Shun appears from there with two goals: return to his own world, and complete Emilio's revenge. What future lies ahead for the two boys trying to survive in Endra, yet raised in two different worlds? (Source: MAL News)

Jougorou Kobato has a habit of inserting himself into other people's problems. After realizing his detective skills are neither wanted nor appreciated, he makes an agreement with his shy friend Yuki Osanai to become ordinary together. Now entering high school, they aim to be perceived as regular people, yet Kobato cannot help but fall back into his deductive ways when faced with everyday mysteries. Unfortunately, mundane occurrences are not all the duo stumbles across. As they go through their school days trying to avoid drawing attention to themselves, Kobato and Osanai at times get caught up in incidents that put their plan of a peaceful, average life at risk.

Tarou Kabakura, a third-year high school student and captain of the boys' volleyball team, is constantly being harassed by his underclassman Hanako Koyanagi, who is in charge of the girls' team. Koyanagi insists that since the girls have a match coming up, Kabakura should give up the courts to let them practice. When he refuses, she pulls out photographic evidence exposing his secret hobby. With the danger of his entire team finding out about his otaku interests looming over him, Kabakura agrees to hand over the volleyball courts to Koyanagi, giving her some private coaching as well. As the two grow closer, they begin to forge an everlasting bond. Third OVA—covering the "employee trip" chapter(s) from the sixth tankouban volume—will be bundled with the special edition of the 11th and final volume of the manga which ships on October 14, 2021. (Source: MAL News, edited)