Danganronpa Gaiden: Killer Killer , originally known simply as Killer Killer for its first volume, is a Japanese manga series written by Kazutaka Kodaka and Yōichirō Koizumi and illustrated by Mitomo Sasako. It was published by Kodansha in the magazine Bessatsu Shōnen Magazine from March 8, 2016 to May 9, 2017, and collected in three tankōbon volumes. The series focuses on Misaki Asano, a young woman assigned to the Future Foundation's 6th branch, dedicated to murder investigations in the midst of "The Tragedy", as she is teamed up with fellow investigator Takumi Hijirihara, a secret serial killer who only kills other killers, for the honor of Mukuro Ikusaba.

Danganronpa is a Japanese video game franchise created by Kazutaka Kodaka and developed and owned by Spike Chunsoft. The series primarily surrounds various groups of apparent high-school students who are forced into murdering each other by a robotic teddy bear named Monokuma. Gameplay features a mix of adventure, visual novel, detective and dating simulator elements. The first game, Danganronpa: Trigger Happy Havoc, was released for the PlayStation Portable in 2010.