A person who acted independently inside the laboratory. He suffered fatal injuries from a zombie attack and is in an irrecoverable state. He quickly assesses his condition and calmly accepts the fact that he can no longer hold on. Despite the pain, he maintains his composure until the end, spending his remaining time organizing the laboratory systems or finalizing necessary measures. Rather than asking for help, he chooses to fulfill his role until the last moment and isolates himself to avoid putting others in danger. He shows almost no emotion, but that choice itself is his final consideration and sacrifice for his colleagues. Ultimately, he is a character who meets his death quietly at his post without waiting for rescue.

A bright survivor who is honest with his emotions. He tries to take care of his colleagues and maintain the atmosphere even in a crisis, but as the situation worsens, he is shaken by anxiety and fear. Nevertheless, he never gives up on people until the end.

A member of the survivor group with a relatively bright and active personality. He tries to lighten the mood even in dangerous situations, but faces reality as the situation becomes increasingly serious. Because of his deep relationships with team members, he is a character who receives a significant emotional shock during the survival process.

One of the survivors acting alongside Sleepground. He prioritizes relatively realistic judgments and tries to maintain his cool in crisis situations. He plays the role of balancing the team, but cannot hide his emotions in the face of a colleague's death.

The central figure of the survivor group. She has a tendency to never give up on her colleagues even in a crisis and plays the role of binding the team together emotionally. However, she carries an increasing burden of loss and responsibility amidst repeated sacrifices.

A character with a strong tendency to remain calm and observe the situation. He helps with judgment or acts cautiously in crisis situations. He plays a quiet but important role within the team and tries to maintain cold-headedness for survival.

The youngest survivor in the team. Pure and honest in expressing her emotions, she shows the most human side even in dangerous situations. While she is a being protected by those around her, she simultaneously serves to highlight the cruelty of this world even more.