|Status||Deceased by Episode 5)|
|Played by||Alisa Sakamoto|
Mami was a friendly yet emotional person who became close with her inmates and wanted to get to know Miki better when she saw another side Miki kept hidden away. She had dreams of becoming a bride and was upset that her boyfriend had broken up with her.
Mami was introduced to Miki after she was transferred in. A day later, she was given a letter from her boyfriend breaking up with her, causing Mami to break down. A few days afterward, the new director of the facility, Shirakawa establishes some rather simple but strange rules. When Miki breaks up a fight with one of her roommates Kayo Miyata and another inmate, Mami notices this and gives a figure house to her hoping she would have a good life and family. When Mami rushed to get water, she is caught by Shirakawa and as she had broken one of his rules she was tortured by being shocked to death with her body left outside the facility with Shirakawa calling it an escape attempt. Her roommates don't believe this, starting the events of the escape and the eventual destruction of the facility.