Mary Saotome is the deuteragonist of Kakegurui and also the protagonist of the Kakegurui Twin spin-off . She is a student at Hyakkau Private Academy and a classmate of Yumeko Jabami and Ryota Suzui, who is the first character in the entire series to challenge Yumeko and lose to her.
In the beginning, Mary is shown to be incredibly sadistic and perverted, such as how she treats her classmate Ryota Suzui after he becomes a "pet" due to her low social status at the academy, and cruelly taunts her comrade. opponents throughout their gambling. He also proved to be extremely selfish both in and out of matches, constantly relying on his victory. Mary also has a habit of making fun of and laughing at her opponents, especially when a match seems to be her victory.
After losing to Yumeko Jabami and experiencing the life of a pet, Mary desperately tried to regain her status at the academy with no other goal. Shortly after being humiliated, Mary ends up losing her pride, suffers a mental breakdown during her match with Yuriko, and falls into a state of pain and shame. after regaining his status, he seems to be less arrogant and ruthless at the moment, sometimes only annoyed by Ryota's cowardice or Yumeko's reckless behavior, however he still cares deeply for them. He also developed a huge hatred for the student council, wanting them to pay for what they did to the pets.