Chloe is a yellow eyed, short haired, black cat owned by Alyssa.
Alyssa initially takes her to Naomi Kimishima when Chloe isn't feeling well, knowing Naomi is a doctor. Chloe is Alyssa's only friend and and is always seen with her, she also has a habit of swallowing things that she shouldn't.
While Alyssa is hospitalized at Resurgam, Chloe is with her and Alyssa shows her to Tomoe Tachibana. Concerned about inflamations in her mouth, Tomoe and Naomi perform an endoscopy to investigate. It turns out that Chloe had swallowed bone fragments that were infected with the Rosalia Virus, and under the bones there were colonies of the virus. After a successful operation, the bone fragments were sent for examination.
The fact that Chloe had swallowed the bone infected with Rosalia gave Tomoe useful insight as to how the virus behaved, allowing her to successfully extract viral colonies for biopsy.
Is is unknown what happened to Chloe after the endoscopy, but it's highly likely she returned to Alyssa.
- During the briefing for Chloe's endoscopy, it's revealed Chloe is 3 years old, is 20 inches long and weighes 6.7 pounds.