Caroline has a very classical tsundere (someone who acts mean-spirited and aloof to disguise any affectionate feelings) attitude towards the protagonist. Additionally, she doesn't seem to hold the protagonist in very high regard, as she refers to him as "inmate," and kicks him into the Velvet Room whenever he goes to enter. She is generally ill-tempered and impatient, even after the twins' Confidant levels up and she grows to respect the protagonist as a friend. There are certain inconsistencies between how she seems and her real personality, and as according to Justine, she was mortified when she first witnessed Persona fusion and practiced intimidating poses to use on the protagonist but is too embarrassed to use them. She tends to speak to Justine in a demeaning manner.

Justine, in contrast, appears to be calm and soft-spoken, but still treats the protagonist as her prisoner, often addressing him in a condescending tone. Unlike her sister, she will calmly escort the player to their cell. She is the first to question what their true purpose is, and realizes something is amiss with possessing an intricate bookmark but having no books to read. While guarding an entrance to the Velvet Room, she whittles away at her boredom by spinning her clipboard.