Rika is a 33-year-old journalist working at the Shūmeisha publishing company in Tokyo. Living alone in a diminutive apartment, she dedicates all her time to her career and relies entirely on convenience store meals and client dinners. Her structured, restrictive lifestyle fractures when she begins investigating a famous convicted killer and food blogger, leading her to experiment with cooking and eating rich foods. The subsequent physical changes force her to confront society's expectations of women.

Manako is a former popular food blogger currently imprisoned and awaiting a retrial for the alleged murders of three men she met online. She is deeply passionate about high-quality food, cooking, and indulging her physical desires. She outright refuses to conform to Japanese society's strict beauty and weight standards for women. During interviews, she uses recipes and culinary assignments to maintain absolute control over the conversation.

Reiko is Rika's best friend from university who recently quit her beloved career to focus entirely on starting a family. Her shift toward traditional domesticity creates a rift between her and Rika, especially as Reiko begins rapidly losing weight to fit societal expectations. Despite their recent differences, she remains fiercely loyal and perceptive, offering crucial advice regarding Rika's investigative work.

Makoto works in the books department at the Shūmeisha publishing company and is Rika's boyfriend. He maintains a casual relationship with Rika, initially appreciating that she does not expect traditional domesticity from him. He is highly critical of women who do not maintain strict beauty standards, regularly judging both female celebrities and Rika's changing body.

Yoshinori is a news agency editor and one of Rika's most reliable professional contacts. He regularly meets with Rika for food and drinks to offer story tips and career advice. He is an approachable, sympathetic figure who genuinely supports Rika without judging her appearance or eating habits, occasionally offering her the use of his empty spare apartment.

Yū is a junior colleague of Rika's at the Shūmeisha publishing company. She often offers enthusiastic encouragement to Rika in the face of negative feedback from readers. She frequently wears merchandise for the girl band Scream and bonds with others over pop culture.

Ryōsuke is Reiko's husband who works for a confectionary company. He enjoys his wife's domestic efforts and high-quality cooking but remains largely unaware of her internal struggles. He later attempts to locate Reiko when she goes missing during an unexplained trip.

Misaki is Rika's single mother who raised her alone following a divorce. She spends much of her time caring for her ailing, demanding father, leading a generally solitary and difficult life. She appreciates when Rika makes an effort to cook simple meals for her.

Kitamura is a male colleague of Rika's at the publishing company. He can be highly critical of Rika's journalistic methods and closely monitors her professional conduct regarding her high-profile interviews with Kajii.

Anna is Manako Kajii's sister who lives in their hometown of Niigata. She relies heavily on her mother and harbors difficult memories of her sister's past, particularly regarding an incident with a local older man.

Masako is Manako and Anna's mother. She maintains the family home in Niigata and historically fixated on dieting, an obsession that heavily influenced her daughter Manako's opposing views on food and indulgence.

Tokio is the last man to die while involved with Manako Kajii. He frequently took Kajii to the opulent French restaurant Robuchon before his death, which the defense argues was an accident linked to his depression.

Hatoko is the sister of Tokio Yamamura, one of Manako Kajii's alleged victims. She provides a perspective on the victims that catches Rika's journalistic interest and later assists Rika with real estate matters.

Shirō is a man who housed Manako Kajii just prior to her arrest. He becomes a subject of intense suspicion for Reiko, who believes he may have assisted in the alleged murders due to his proximity to the killer.

Mizushima is Rika's former colleague who transitioned to work in the books department at Shūmeisha. He is highly supportive of Rika and explicitly reassures her regarding her changing physical appearance.

Taiichi is a dairy farmer who lived near the Kajii family in Niigata. He views Manako as a strange, reclusive girl who lacked friends during her youth, offering Rika a starkly different perspective on the glamorous food blogger.

Known as Madame, Miyuko runs Le Salon de Miyuko, the women's cooking school that Manako Kajii previously attended. She guides her students through traditional, complex recipes and eventually lends Rika her personal cookbook.

Chizu is a student at the cooking school who views the classes as an escape from her regular life. She provides Rika with critical insight into how the other women perceived Manako Kajii's intense approach to cooking.

Saya is Yoshinori Shinoi's daughter. Her past struggles with an eating disorder weigh heavily on her father's conscience, and she eventually integrates into Rika's new social circle.