Atsuko Urameshi is the mother of the series' protagonist, Yusuke Urameshi. She is a young single mother, having given birth to Yusuke when she was only fourteen years old, making her twenty-eight or twenty-nine years old during the events of the story. Her life has been marked by hardship, and she is frequently depicted as being irresponsible and struggling with alcoholism, often shown either drunk or passed out.

Despite her flaws, Atsuko genuinely loves her son. Their relationship is often strained and volatile, with Yusuke rarely getting along with her due to her neglectful tendencies. However, the depth of her love becomes undeniable when Yusuke dies in a heroic accident. At his wake, her profound grief and open weeping reveal her true feelings, a sight that helps Yusuke understand the love she has always had for him but struggled to express. This event is a turning point for her character. After Yusuke is revived, she becomes significantly more protective and involved in his life, living in terror of losing him again. In the anime, this manifests as her forcing him to attend school and not skip class, a reversal of her earlier laissez-faire parenting.

Atsuko's primary motivation is a deep-seated desire for her son to have a better life than she did. She wants him to turn out better than her, even if she feels she has failed in guiding him toward that path. Her role in the story is largely that of an emotional anchor for Yusuke, representing his ties to the human world and the life he left behind. She is most prominent in the early arcs, particularly the Spirit Detective Saga. In the manga, she has a more active role, attending the Dark Tournament alongside Keiko, Botan, and Shizuru Kuwabara, and even participating in a fight against a demon security guard, proving she is a capable fighter. In the anime, however, many of her scenes are omitted, and her role is often assumed by the character Shizuru Kuwabara.

Key relationships define her character. Her bond with her son is the most significant, evolving from one of mutual frustration to a more caring, if still unconventional, connection. She also has a friendly relationship with Keiko Yukimura, Yusuke's childhood friend and love interest. In the manga, it is suggested that Atsuko has connections to the local Yakuza or underworld figures, which she uses to solve problems, such as when she strong-arms the school chairman into readmitting Yusuke. The identity of Yusuke's father, her ex-husband and former lover, is never revealed, and he is largely absent from their lives.

One notable ability that Atsuko possesses is spiritual awareness. Like her son, she can see and sense demons and other supernatural entities, though this ability is primarily showcased in the manga storyline rather than the anime. In the manga, she also demonstrates unexpected physical strength and fighting prowess, able to hold her own in a skirmish at the Dark Tournament. Her character represents a complicated portrait of motherhood, sacrifice, and regret, showing that even a deeply flawed parent can harbor genuine love and a fierce desire for their child's success.