Gouriki plays the lead character Kamiwatari Kotone who was a geigi in Kyoto sentenced to five years in prison (the lowest sentence for this crime) for the murder of her fellow geigi while in a drunken stupor. Although all the evidence pointed to Kotone as the murderer, she insisted that she did not do it but to no avail. During her imprisonment, Kotone is bullied by other inmates but doesn't think much of it because she had been used to the tough disciplinary actions by her seniors in the geigi world. Unknown to the others, Kotone has a lot of strength, can easily fight anyone with aikido, pretends to be stupid but is actually very smart, fluent in English and French and has very good hearing. At the end of the drama, the reason why Kotone was framed for the murder will also be revealed.
Yamaguchi Sayaka will play the role of Kususe Tsukasa who is in prison for violating the political funds regulation law and fraud. She used to be a political secretary, has an air of secrecy and behaves like a suave man just like the Takarazuka actresses who play male roles. Her nickname is Zuka and she is a cleanliness freak.
Triendl Reina will play Ichikawa Sara who is the youngest in the group and a single mother but has been in prison the longest. She used to be a delinquent thus earning the nickname Motoyan and was sentenced to jail for killing her husband who subjected her to domestic violence. When Kotone enters the prison, she is the first to instigate the others to bully her and very frightening when she flares up.
Hiraiwa Kami plays Tsuda Sakurako who ended up in jail for killing a man for his inheritance. Although she is serving a life sentence with no possibility of getting out, she is a narcissist who is obsessed with her looks and has the nickname Ero Onna (Erotic Woman). Although she calls herself an expert in sex and has absolute confidence in her looks, the others see her as no more than an ordinary middle-aged woman.
Hashimoto Manami will play Yajima Chizuka who underwent extensive plastic surgery to attain her current looks and used to work as a nurse at a famous plastic surgery clinic before she killed the patient she was having an affair with. She has the nickname Nurse and is very cynical and always suspecting that other people are talking behind her back. Due to her tendency to imagine herself as a victim and getting hysterical, she is viewed as a negative monster by the others.
Kino Hana will play the oldest inmate in the same room named Hiratsuka Ume who was taking care of her sick husband but couldn't take it anymore and killed him. She does not get involved in the bullying towards Kotone and goes about her daily duties diligently. Her nickname is Umeboshi (pickled plum).
Last but not least, Adachi Yumi will play Sakamoto Natsu who always eats at restaurants without paying thus nicknamed as Kui-nige (dine and dash) and is the No.1 information hub in the prison who knows everything. Although she appears kind and teaches Kotone the rules about prison life, she is actually plotting to create trouble for Kotone behind her back.