"Tail of Two Sisters" is a psychological horror anime that delves into themes of family, trauma, and the supernatural. The narrative centers on two sisters, Su-mi and Su-yeon, who return to their family home after spending time in a mental institution. Their father, Moo-hyeon, has remarried, and their stepmother, Eun-jo, becomes a central figure in the unfolding drama. The house itself is eerie and oppressive, with a history of tragedy and secrets that gradually come to light.

Su-mi, the older sister, is fiercely protective of Su-yeon, who is fragile and often unwell. Su-mi harbors deep resentment toward Eun-jo, believing her to be cruel and manipulative. As the story progresses, the line between reality and hallucination blurs, with Su-mi experiencing disturbing visions and memories that suggest a darker past. The sisters' bond is tested as Su-mi becomes increasingly unstable, and Su-yeon begins to exhibit strange behavior, raising questions about their shared history and the true nature of their relationship.

The plot is driven by a series of unsettling events, including ghostly apparitions, unexplained noises, and cryptic interactions between the characters. Flashbacks reveal fragments of the sisters' childhood, hinting at abuse, neglect, and a traumatic incident involving their mother. These revelations complicate the narrative, as it becomes unclear whether the supernatural elements are real or manifestations of Su-mi's deteriorating mental state.

Eun-jo's role is ambiguous, with her actions oscillating between kindness and cruelty, leaving her true intentions uncertain. Moo-hyeon, the father, is distant and emotionally detached, further isolating the sisters and contributing to the atmosphere of tension and unease. The house itself functions almost as a character, with its labyrinthine layout and oppressive atmosphere amplifying the psychological horror.

As the story reaches its climax, the layers of deception and trauma are peeled back, culminating in a shocking revelation about the sisters' past and the true nature of their suffering. The ending is open to interpretation, leaving viewers to piece together the final truths about the characters and their fates. "Tail of Two Sisters" is a haunting exploration of familial bonds, mental illness, and the lingering effects of trauma, told through a narrative that masterfully blends psychological tension with supernatural elements.