Ikuko Tsukino is the wife of Kenji Tsukino and the mother of Usagi and Shingo Tsukino in present-day Tokyo, residing in the Azabu-Juuban district of Minato-ku. As a dedicated housewife, she is often seen managing the household and is known for her cooking, with her lemon pie considered her signature dish. Her name is spelled with kanji meaning "education child" and "moon field".

In terms of appearance, Ikuko has long, curly hair which has been depicted in various colors across different media, including shades of lavender, dark blue, pink, and brown. She typically wears easygoing home attire such as a blouse and skirt covered by an apron, along with slippers. Her hair is often styled in a half-loose ponytail held by a clip.

Ikuko is characterized as a nurturing and caring parent who deeply loves her family, though she can also be strict and authoritarian when the situation calls for it. Her primary motivation is to see her children succeed, particularly wanting Usagi to do well in school and make it through her education. This is famously demonstrated in the first episode and first act of the series, where she kicks Usagi out of the house after she brings home a low score of 30 percent on an English test, hoping to force her to study more seriously. Despite her frustration with Usagi's lazy and crybaby tendencies, she consistently supports her daughter, giving advice on various topics like dieting and modeling auditions.

Throughout the story, Ikuko plays a supporting role as the mother of the protagonist. Her primary dramatic function is to provide a normal, grounded home life, creating a contrast with Usagi's secret identity. In a notable moment during the Sailor Moon SuperS season, the enemy Hawk's Eye targets Ikuko because of his appreciation for older women and his belief that the mystical Pegasus might be hiding within her dream. He attempts to romance her with a fabricated sob story, but Super Sailor Moon and Super Sailor Chibi Moon intervene to rescue her.

Ikuko is completely unaware that her daughter is the superheroine Sailor Moon, nor does she know that Usagi is the reincarnation of a Princess from a past life or destined to become a Queen in the future. Usagi keeps her double life a secret from her entire family. However, in the Sailor Moon Cosmos storyline, as Usagi prepares to leave home for a final battle, an emotional Ikuko cries, expressing a feeling that her daughter might never return, hinting at a mother's intuition of the danger ahead.

Her key relationships are centered on her family. She lives with her husband Kenji and her two children Usagi and Shingo. When the future character Chibiusa, who is secretly Usagi's future daughter, travels to the past, Ikuko is brainwashed into believing Chibiusa is her niece and welcomes her into the home, caring for her as if she were her own daughter. Similarly, when the young girl Chibi Chibi appears, Ikuko adopts her as well, believing her to be a younger sister for Usagi. Ikuko also encourages Usagi's budding romance with Mamoru Chiba, suggesting she bring him over to meet the family, and expresses sadness when the two briefly break up.

Regarding her development, Ikuko remains a consistent figure throughout the series, never learning the truth about her daughter's heroic activities. One subtle piece of personal background information is revealed when Usagi notes that her mother has never had a cavity in her 36 years, indicating Ikuko's age is 36 toward the end of the manga storyline.

Ikuko possesses no supernatural abilities or combat skills, as she is a normal human civilian. Her notable abilities are domestic in nature; she is an excellent cook, though she admits to having no proficiency in sewing, a humorous trait she shares with her daughter. She also has a fondness for collecting photographs and keeps a photo album filled with family pictures.