Danganronpa Gaiden: Killer Killer

Danganronpa Gaiden: Killer Killer (ダンガンロンパ 害伝キラーキラー), previously known only as Killer Killer (キラーキラー), is a manga spin-off connected to Danganronpa 3: The End of Hope's Peak Academy.

The manga was debuted on March 8, 2016 in Bessatsu Shōnen Magazine's April issue. The manga is illustrated by Mitomo Sasako, with scenario written by Kazutaka Kodaka and Yōichirō Koizumi.

The of Danganronpa events places it after the events of Danganronpa Another Episode: Ultra Despair Girls and before the events of Danganronpa 2: Goodbye Despair.

Synopsis
In response to The Biggest, Most Awful, Most Tragic Event in Human History, an organization called Future Foundation was created to combat the chaos still present even after the death of The Mastermind.

Misaki Asano is a new recruit, working as a special investigator for the 6th Division's Special Case Criminal Investigation Unit, a bureau dedicated to solving the most bizarre and challenging murder cases. Alongside her partner, Takumi Hijirihara, they aim to combat despair one case at a time. Their most challenging case is that of the mysterious Killer Killer, a bizarre serial killer who targets other murderers.

Future Foundation's 6th Division

 * Takumi Hijirihara
 * Misaki Asano
 * Juzo Sakakura
 * Ikue Dogami
 * Mekuru Katsuragi
 * Kenji Tsuruhashi

Future Foundation's Members

 * Kyosuke Munakata
 * Kyoko Kirigiri
 * Ruruka Ando
 * Sonosuke Izayoi

Serial Killers

 * Momomichi Ito
 * Rei Shimizu
 * Ted Chikatilo
 * Eiichiro Saiyama
 * Mimiko Tomizawa
 * Mukuro Ikusaba
 * Shūji Fujigawa

Supporting Characters

 * Super High School Level Make-up Artist
 * Junko Enoshima

Minor Characters

 * Kinari Kunugida
 * Sakuma Fujii
 * Chusuke Oyama
 * Nobuo Takeda
 * Monokuma

Trivia

 * It was not revealed that Killer Killer existed in the Danganronpa universe until Chapter 3, when the manga's full title was revealed in the June issue of Bessatsu Shōnen Magazine.
 * All 3 compilation volumes include art referencing Danganronpa: Trigger Happy Havoc.
 * Volume 1 features Takumi murdered in the style of Sayaka Maizono.
 * Volume 2 features Misaki hung by ropes to a frame, in the style of Chihiro Fujisaki.
 * Volume 3 features Takumi on a throne, wearing Junko Enoshima's crown.
 * There are also several references to the murders featured in Danganronpa: Trigger Happy Havoc in Chapter 3, in which Eiichiro Saiyama is a documentary manga artist drawing manga about The Tragedy. Victims hung by ropes in the style of Chihiro Fujisaki can be seen, and Eiichiro is executed in a murder mimicking Mukuro Ikusaba's death.
 * The mask of Sparkling Justice, a serial killer mentioned in Danganronpa 2: Goodbye Despair, is on display in Eiichiro Saiyama's room in Chapter 3. Because the identity of Sparkling Justice is unknown, it is possible that Sparkling Justice and Killer Killer may be the same person, as they both have the same (murdering other killers), which is supported by the fact that the name of Sparkling Justice in the original Japanese release of Danganronpa 2 is Kirakira Seigi (キラキラセギ). It is unknown if this is intentional or simply a reference.