|“||You survived just by chance.||”|
Shiiko Aosoi (青襲 椎子 Aosoi Shīko ) was a lab technician at Saint Isidore University. Her whereabouts makes her quite mysterious since she has been locked inside the chemistry labs.
She has long light-colored hair and wears an unbuttoned lab coat which covers a lined turtle-neck sweater. She is usually smoking a cigarette.
Aosoi is socially awkward and prefers to keep inside and in front of her computers, rather than go outside talk to people face-to-face. Once she meets the cast, she regularly gives other characters uncomfortable stares and replies to questions with blunt remarks. She does not care about invading the personal space of others, and is quick to declare that Kurumi is infected, regardless of what others might think. She is shown to have no remorse or problem with killing zombies at close range, using a hammer and screwdriver.
She seems to be the remaining surviving staff member of the University and has kept her existence hidden from the Melee Fight Club and Fallen Crew so as to not be dragged into their conflict. She has been secretly researching some imprisoned zombies in her chemistry lab in order to find out more about the infection, but reveals her existence and continuing research discreetly to Miki over the intercom when she came exploring.
After the Melee Fight Club falls apart, Aosoi accompanies the School Life Club to Randall Corporation Headquarters to learn more about the infection. There, she reads over notes left behind by Randall scientists and realizes that they had abandoned hope for the region, speculating Randall will probably burn all infected areas in an attempt to destroy the virus, speculating that a similar incident had occurred years ago.
From Randall's notes, Aosoi explains the probable origin of the infection and outbreak to the girls and gives them a smartphone with Boman-kun, where one of its features was a truth-or-lie detector. Learning that they could contact Randall Corporation to let them know there were survivors, the group does just that. Upon being told that help is on the way and to stay put, Boman-kun reveals the operator was almost guaranteed to be lying, and Aosoi reveals what she predicts Randall would actually do. When the girls decide to tell Randall about Kurumi, Aosoi is hesitant, asking Yuki what they would do if Randall would not comply with their one request to all stay together. She warns Kurumi that Randall likely has their own Boman-kun to see if they are lying or not. In this call, the operator agrees to send help immediately this time and that they will all be able to stay together. To the group's horror, Boman-kun reveals that although Randall believes them that Kurumi is a special case in terms of her reaction to the infection, everything about help and staying together were lies.
The group leaves Randall HQ, just missing the helicopter sent by Randall to acquire Kurumi. The group acknowledges that they are now being chased and need to keep moving, as they hear Randall soldiers in the streets shooting infected. The group receives a call from a group named the Randall Council, which Boman-kun shows that they are telling the truth about wanting to help them. The girls make their new goal to evade Randall Corporation and meet up with the Randall Council.
Aosoi is revealed to be succumbing to the infection and knowing she would slow the group in their chase with Randall, stays behind and handcuffs herself to a pole so she cannot harm the girls if she turns. She records some last notes on her cellphone for the girls to watch and listen to after she dies. Before the group leaves the area, Miki finds her and kills her in a coup de grâce.
After her death, Miki reveals that the "Randall Council" was a fabrication made by Aosoi and never existed. Despite Aosoi's last message claiming her coldness and that she had given them false hope, the group speculates Aosoi did that to keep the girls' spirits up and would not have done so if she believed there was no chance of curing Kurumi or surviving.
It's later revealed that Aosoi figured out the origins of the zombie virus and left this information in her notes, which the girls discover after unlocking the cellphone's password; her full name. From this, the girls deduce that the virus originated from Nazake Marsh, the source of the Kuchina River that flows through Megurigaoka, and that there is another chemical in the water that neutralizes the virus, which they had been drinking the whole time while at Megurigaoka High due to the school's water tank drawing the Kuchina River. They thus decide to go back to the school in hopes of using the water in the tank to cure Kurumi.
|Character||What Aosoi calls them||What they call Aosoi|
- Main article: Category:Aosoi Shiiko
- Aosoi speculates that the zombie infection was caused by a large-scale, pre-planned aerial attack; with the survivors being temporarily immune to it.