On the planet after the disaster, the young boy Ye Yu went to Embers City for an assessment in pursuit of his dream. He faces numerous murderous intentions and mysteries, and the truth behind them is impossible to unravel.

Grade schooler Yuuta Tomonaga stumbles upon Deckerd, a humanoid robot under construction by the Japanese police, built to fight advanced forms of crime. Yuuta's constant contact with Deckerd gives the robot a "heart," or personality; when Yuuta is recruited as the "boss" of the "Brave Police" as a result, a true human/robot partnership occurs.

After Jinta and Suzune ran away from their home as children, they were taken in by Motoharu—the virtuous sentinel of Kadono Village—and his daughter, Shirayuki. The settlement was ruled by its shrine maiden, Itsukihime, whom only a select few were allowed to interact with. When Itsukihime passed away, Shirayuki was appointed in her place. Wishing to stay in contact with her, Jinta worked diligently for years and was finally selected as the next sentinel. As the protector of the village, Jinta's duty is to eliminate any threats. One day, he encounters a demon in a nearby forest. At the end of the battle, the demon makes a proclamation about the destined ruler of all demonkind. He attaches his severed arm to Jinta, turning him into an unaging demon man. By the time Jinta comes to, Kadono is on fire. Suzune has transformed into the demon from the divination, and due to a series of misunderstandings, she murders Shirayuki and flees. Devastated, Jinta cannot forgive Suzune for her actions; he departs on a journey to find her. As Jinta travels around Japan across the eras, he endeavors to protect as many people as possible from aggressive demons. In his quiet moments, he contemplates what he should do when he once again faces his childhood friend.

In an alternate 2023, the Your Forma, a miraculous "smart thread" technology initially developed to treat a massive outbreak of viral encephalitis, has become an integral part of daily life. But these convenient devices come with an invasive drawback—they record every sight, sound, and even emotion their users experience. For electronic investigator Echika Hieda, diving into peoples' memories via the Your Forma and hunting for evidence to solve the toughest crimes is all part of a day's work. The problem is, she's so good at what she does that her assistants literally fry their brains trying to keep up with her. After putting one too many aides in the hospital, the top brass finally furnish Echika with a partner on her level, a brilliant yet cheeky android named Harold Lucraft. Does this unlikely duo have what it takes to resolve their mutual suspicions and avert a deadly technological infection from sweeping across the globe before it's too late?