Karin, a DNA operator from the future, is on a mission to change the course of History by stopping Junta Momonari from becoming the Mega-Playboy who fathered 100 children and led to the overpopulation of the world. But Junta is no playboy; in fact he is allergic to girls. But when Karin shoots him with the wrong DNA-altering bullet, he starts sporadically becoming the Mega-Playboy capable of charming any woman. Karin must try to restore the situation to normal before the change to Mega-Playboy becomes irreversible. (Source: ANN)

The "loosely science-fiction adventure" is set in the summer sometime in the 21st century. Tokyo's Shinjuku ward has become a wasteland, void of all humans due to an unexplained catastrophe. What remains are these strange creatures such as "Donyatsu," the half-cat, half-doughnut hybrid, and "Begaru," a feline bagel composite. (Source: ANN)

The once peaceful city-state of Lisvalletta has found itself beset by a dangerous new drug called Anthem. The side effects of the drug allow the user to enter a state of Overdrive, wherein they mutate into superpowered beasts with inhuman abilities. With the police powerless to stop this new threat, the responsibility falls upon the Special Crime Investigation Unit SEVEN-O. To offset the dangers of this work, the investigators work under the patented "Double Decker" system, which requires them to team up in "buddy cop" pairs. As a child, average police officer Kirill Vrubel fantasized about being a hero who would save his school from a random terrorist attack. His chance to be a hero arrives when his landlady blackmails him into searching for her lost cat. Upon arriving and falling asleep in an abandoned warehouse, Kirill finds himself in the middle of a hostage situation involving an Anthem user. By teaming up with SEVEN-O detective Douglas "Doug" Bilingam, Kirill earns his spot as the newest member of SEVEN-O. Now, with the help of this secret organization, he may finally achieve his dream of becoming a hero. [Written by MAL Rewrite]

During the final episode pre-screening event on Friday, it was announced that Double Decker! Doug & Kirill TV anime will get three extra episodes. Titled Double Decker! Doug & Kirill: Extra, the three episodes will be streamed via Bandai Channel and other streaming websites between February and April 2019. The Blu-ray and DVD for the extra episodes will also be released on May 24, 2019. (Source: MAL News)