When tragedy is about to strike, Satoru Fujinuma finds himself sent back several minutes before the accident occurs. The detached, 29-year-old manga artist has taken advantage of this powerful yet mysterious phenomenon, which he calls Revival, to save many lives. However, when he is wrongfully accused of murdering someone close to him, Satoru is sent back to the past once again, but this time to 1988, 18 years in the past. Soon, he realizes that the murder may be connected to the abduction and killing of one of his classmates, the solitary and mysterious Kayo Hinazuki, that took place when he was a child. This is his chance to make things right. Boku dake ga Inai Machi follows Satoru in his mission to uncover what truly transpired 18 years ago and prevent the death of his classmate while protecting those he cares about in the present.

Life is not going well for 28-year-old Kyouya Hashiba. Having left his office job to pursue a career in the video game industry, his internship at a popular game studio abruptly ends, leaving him unemployed and forcing him to move back in with his parents. Additionally, his jealousy toward the success of the Platinum Generation—a group of similarly-aged creators—has caused him to regret his decision to attend a traditional university instead of an arts college. Even though he believes there are no second chances in life, Kyouya is suddenly given one when he wakes up one day and finds himself 10 years in the past. Instead of choosing business school like he originally had, Kyouya decides to pursue his passions and attends the Oonaka University of Art. There, he meets classmate Eiko Kawasegawa, the woman who had hired him as an intern in the present, alongside his new housemates and future Platinum Generation members: underachieving artist Aki Shino, aspiring singer and actress Nanako Kogure, and naturally-gifted writer Tsurayuki Rokuonji. With each project they complete together, Kyouya and his friends venture closer to discovering their true potential as creators and remaking their lives into the ideal versions they desire.

When ordinary high school student Aoba Watase is suddenly targeted by a giant robot known as a Valiancer, he is saved by his mysterious classmate Hina Yumihara. After revealing that she and their robotic enemy are from the future, Hina suddenly propels Aoba 70 years forward in order to prevent his death. Upon arrival, Aoba finds himself in the cockpit of a Valiancer called Luxon, stuck in the midst of a firefight between the military forces of the Free Pact Alliance (FPA) and Zogilia Republic. After he shows high compatibility with an FPA pilot named Dio Weinberg, the two perform a successful coupling, allowing them to share experiences and subsequently increase their capabilities and skills. Although Aoba is able to survive this unexpected battle, he is taken into custody by the FPA ship Cygnus, who wishes to interrogate him. While the student's main concern is whether he will ever be able to return home, what he doesn't realize is that he is about to get caught up in a war to protect the world.

The two part finale of Buddy Complex television series deals with the final battle between the Free Treaty Alliance and the space division of Zogiria, lead by an elderly Bizon, as Earth and time itself hang in the balance.