Saki Mizuni (水野 咲,Mizuno Saki) is a first-year student who attends Kyoutoku Academy. She is also a participant of Dead Tube.
At first Mizuno appears to be a sweet and innocent and a very shy girl who had a crush on Machiya. This is later shown to be false when she is revealed to have willingly slept with three other members of the film club at the same time, who believed they were raping her, in exchange for having them commit suicide. She is shown to be sadistic and manipulative. Being apart of Ousima's filming crew for DeadTube, and tries to manipulate Machiya. She would do anything for money. She is also shown as very experienced in sleeping with girls.
She is shown to be an excellent actress, being the actress for the film club and successfully hiding her true personality. She is comfortable being naked around both male and female characters. It is possible that she was a sex buddy with other members of the film club.
Saki Mizuno is a young short teenager. She has long, blonde hair that generally braided. Her eyes are blue and she mostly wears glasses.