The sole survivor of Gensokyo. Having witnessed her best friend Reimu Hakurei and her other close companions being slaughtered by the infected (killing machines), her mental state has completely collapsed. However, deep down, she still harbors thoughts like "I don't want to die" or "If I'm going to die, I'd rather just..." which prevents her from ending her own life. Though her spirit is broken, she actually craves human connection; she is aware that if she found another survivor who comforted her or showed her kindness, she would break down and sob. Her tomboyish way of speaking has faded, and her once bright personality has become quiet and withdrawn. She can still use magic and is capable of fighting, but since the infected were originally human, she is paralyzed by guilt and unable to strike them down. She believes no one else is left alive and has almost given up on ever speaking to another human again.

Reimu, infected by the Clone Virus. While Marisa says she was "killed," she actually meant infected. Her ribbon and accessories are gone, and she has become a perfect killing machine that exists only to slaughter. She still possesses and uses her abilities. She does not speak, but occasionally emits groans that are the remnants of what used to be words.