Natsuko is a 30-year-old unmarried woman living in Tokyo, attempting to balance a minimum-wage job with a budding writing career. Raised in an impoverished, single-mother household in Osaka, she experiences intense visions and memories that blur the line between past and present. She identifies as asexual and lives a socially isolated life, though she maintains a close bond with her sister and niece.

Midoriko is Makiko's 12-year-old daughter. She refuses to speak to her mother out of frustration over their financial struggles and her mother's desire for cosmetic surgery. She meticulously records her fears about puberty and the bodily functions required for reproduction in her journal. Disillusioned with the societal expectations placed on women, she questions the morality of bringing children into the world.

Makiko is Natsu’s 39-year-old sister who works at a hostess bar in Osaka to support her daughter. She raised Natsu after their mother and grandmother passed away and continues to sacrifice her own comfort for her family. Deeply insecure about aging out of her appearance-based profession, she obsesses over saving for a breast augmentation procedure she cannot afford.

Rika is an outspoken and successful novelist who quickly befriends Natsu. As a single mother raising her young daughter alone, she is vocal in her criticism of archaic gender norms and misogyny. She serves as an encouraging model of unconventional, independent motherhood.

Aizawa is a 30-year-old physician based in Osaka who grew up believing the man who raised him was his biological parent. He searches for his anonymous biological father while dealing with intense feelings of alienation. He exchanges emails with Natsu, offering his perspective on the ethics of artificial insemination.

Yuriko is a young woman who discovered her donor-conceived origins in adulthood. She survived severe abuse during her childhood within a highly dysfunctional family. She holds strict anti-natalist views, believing that procreation is inherently selfish and that life is a burden forced upon children without their consent.

Ryoko is Natsu’s driven, unmarried editor who finds satisfaction in her child-free independence. She frequently warns Natsu about the exhaustion that comes with balancing family and career, firmly believing that great artistic achievement requires avoiding domestic responsibilities.

Komi is the late grandmother of Natsu and Makiko. After Natsu's father abandoned the family, Komi took the children in and provided loving, stable care while their mother worked long hours. Her early death from cancer remains a significant source of unresolved grief for Natsu.

Natsu and Makiko's unnamed mother worked relentlessly to support her daughters after fleeing an abusive marriage. She relied on the help of her mother, Komi, to maintain the household before passing away from cancer when her daughters were teenagers.

The abusive and neglectful father of Natsu and Makiko. He refused to contribute to the household and subjected his family to domestic violence before abandoning them when Natsu was seven years old.

Rie is a married woman and one of Natsu's closest friends. She resents the unequal distribution of labor in her marriage and openly admits to struggling with a lack of connection to her young daughter. She stays in her unhappy marriage due to the social stigmatization of single mothers.

Coco is the middle-aged owner of Chanel, the hostess bar where Makiko works. She prioritizes youth over experience, hiring young and conventionally attractive women regardless of their professionalism to appease her male clientele.

Onda is a man who advertises himself online as a direct sperm donor. He targets single women who are legally excluded from artificial insemination clinics in Japan, viewing the process as an opportunity to exercise his personal fetishes.

Suzuka is a hostess in her mid-thirties who was one of Chanel's best workers. She abruptly quit her job after discovering that a younger, less experienced employee was earning a higher hourly wage simply for being younger.

Jing Li is a reserved college student hired by Coco to work at Chanel. She receives higher pay than her older peers simply due to her youth and popularity with the bar's customers.

Naruse is Natsu's former boyfriend. Their relationship ended because Natsu experienced intense distress during physical intimacy, leading Naruse to seek intimacy elsewhere and eventually marry someone else.