Danganronpa Zero is a Japanese light novel written by Kazutaka Kodaka and illustrated by Rui Komatsuzaki. It was published by Seikaisha from September 16 to October 14, 2011, and has been collected in two tankōbon volumes. A prequel to Danganronpa: Trigger Happy Havoc, the novel focuses on Ryoko Otonashi, a student who, as a result of "The Tragedy", has anterograde amnesia and has short-term memory loss. Overseen by the school's Ultimate Neurologist and her childhood sweetheart Yasuke Matsuda, Ryoko becomes embroiled in a vast conspiracy within Hope's Peak Academy, involving the mysterious Izuru Kamukura and "Despair Sisters" Junko Enoshima and Mukuro Ikusaba, as "The Parade" protests arise outside.