Eriko is a thirty-year-old employee at the prestigious Nakamaru trading company in Tokyo, where she manages the import of Nile perch. Despite her immaculate exterior and high salary, she battles profound loneliness and struggles to form lasting female friendships. She lives with her parents in a pristine apartment, relying on rigidly controlled routines to manage the pressures of her corporate career. To cope with her isolation, she becomes intensely fixated on a lifestyle blog, projecting her desire for a carefree life onto its author.

Shōko is a thirty-year-old housewife living in Tokyo who writes the popular lifestyle blog "The Diary of Hallie B, The World's Worst Wife." She deliberately cultivates an online persona of a lazy, carefree slacker to escape the stifling expectations of domestic life and her own dysfunctional family background. While she enjoys the modest income and validation her writing provides, she feels ambivalent about growing her audience and the scrutiny it attracts. She prefers avoidance and passive retreat over confrontation.

Keiko is a disheveled woman who lives in the same Tokyo apartment building as Eriko and works menial night-shift jobs. Following a severe and traumatic falling-out with Eriko during high school, she has completely withdrawn from societal expectations, embracing a life of passive inertia. She serves as a sharp critic of Eriko's artificial behavior, holding a mirror to the destructive consequences of patriarchal pressure.

Yasuyuki is a confident colleague of Eriko's at the Nakamaru trading company. He frequently vocalizes the casual misogyny prevalent in corporate culture, reflexively assuming that women are motivated primarily by jealousy and competition. His relationships tend to be transactional, masking his own emotional immaturity behind a facade of professional arrogance.

Maori is a pragmatic temporary employee operating within the precarious economic reality of modern corporate Tokyo. Unlike her more privileged coworkers, she operates with a keen awareness of class disparities and social hierarchies. She values her female friendships highly and approaches romance with a strategic mindset, seeking financial stability over idealized affection.

Kensuke is a supermarket manager and Shōko's husband. Affectionately nicknamed the "Demon King" on her blog, he is a gentle, stabilizing force who provides the financial and emotional safety Shōko craves. While he supports her creative endeavors, he possesses a protective streak and quickly grows wary of the strange attention her blog attracts.

Satoko is an editor from Shūmeisha who specializes in lifestyle content. She views digital personas purely through a commercial lens, encouraging creators to professionalize and monetize their authenticity. She represents the media forces that capitalize on female insecurities and parasocial internet culture.

Nori is a highly successful superstar blogger who manages internet fame with polished professionalism. She serves as an aspirational figure for newer creators, offering strategies on how to manage personal brands and handle obsessive fans in the digital age.

Hashimoto is a young waiter employed at Shōko's favorite local café. Friendly and attentive, he provides a source of flattering external validation for Shōko, momentarily distracting her from the mounting anxieties in her domestic and digital lives.

Naomi is a Japanese expatriate working as a local coordinator in Tanzania. She facilitates business operations for visiting corporate employees, projecting a genuine warmth and competence that briefly breaks through Eriko's usual social barriers.

Yōhei is Shōko's younger brother, who remains entangled in their family's chaotic dynamics. Like their father, he avoids taking responsibility for domestic crises, reflexively expecting the women in the family to manage the emotional and physical labor of caretaking.

Urumi is Shōko's stepmother. Her erratic behavior and frequent departures from the family home create a cycle of instability, forcing other family members to step in and manage the household in her absence.

Miwa is Shōko's cousin, who has returned to their hometown to act as a full-time caregiver for her chronically ill mother. Navigating her own complicated domestic burdens, she represents the exhausting reality of familial obligation that women are often expected to bear.