On a rainy afternoon, the Detective Boys witness a murder across the street. Barred by traffic, the culprit slips away and Conan Edogawa is left a single clue by a dying detective. Days later, another detective is found murdered in a parking lot, leaving the police rattled. Suspicious that the culprit is one of their own, everyone in the police department without an alibi is suspect. But despite being on high alert, they are outmaneuvered and suffer yet another attack—this time with Ran Mouri finding herself in the crossfire. Traumatized, Ran wakes in the hospital with retrograde amnesia, remembering nothing about her life. Soon released, she struggles to remember her past and grows fearful of not regaining her memories before being targeted by the killer for what she witnessed. As she is guarded by friends and family, it is up to Conan to piece together the clues and find who the murderer is before they strike again.

The countdown to extinction begins on Sunday with the arrival of the Septentriones, otherworldly invaders set on the eradication of mankind. Caught in the crossfire, Hibiki Kuze and his friends join in the war for humanity's survival by signing contracts with demons to become Devil Summoners. Soon, their abilities attract the attention of JP's, an underground agency led by Yamato Houtsuin. Once recruited into JP's, Hibiki and his friends fight and bond alongside other ordinary citizens who are Devil Summoners. However, with each new day, another Septentrione appears to wreak havoc upon Japan. Even if many lives are lost in the process, before that night ends, the young summoners must defeat the invaders at all costs.

Patty Lowell—the lost heir of a prestigious family—is found at an orphanage, and J.D. Morrison brings her to his acquaintance Dante, the owner of a business called Devil May Cry. Dante takes on so-called odd jobs, and at Morrison's request, he agrees to become a bodyguard for Patty. Begrudgingly, he sets out to deliver Patty to her family, though he is a bit annoyed with a job that essentially amounts to babysitting. While Dante seems like a lazy good-for-nothing, he is actually a prolific demon hunter, which comes in handy when demons begin pursuing Patty. Soon enough, Dante realizes that there is more to this case than meets the eye, and he makes use of his particular skill set in order to keep Patty safe.

This is a special introductory episode of Detroit Metal City.