"Alice or Alice" is a slice-of-life manga series that centers around the daily lives of twin sisters, Ritsu and Rina, who share the nickname "Alice." The twins live with their older brother, a hardworking office worker who takes on the role of their caretaker. The story unfolds in a lighthearted and comedic manner, focusing on the interactions between the siblings and their friends, particularly a classmate named Yuzu, who harbors feelings for the brother.

The narrative primarily explores the playful and often chaotic dynamics of the twins, who, despite their identical appearances, have distinct personalities. Ritsu is more reserved and responsible, while Rina is energetic and mischievous. Their contrasting traits lead to humorous situations as they navigate school life, household chores, and their relationships with others. The brother, though often exasperated by their antics, remains a supportive and caring figure, balancing his work responsibilities with his role as a guardian.

Yuzu, a close friend of the twins, frequently visits their home, adding another layer of comedy and mild romantic tension to the story. Her attempts to win the brother's affection are met with mixed results, often leading to amusing misunderstandings. The series maintains a light tone throughout, with episodic chapters that highlight the characters' everyday adventures, from school events to family outings.

The manga emphasizes themes of family, friendship, and the small joys of daily life, presenting a wholesome and relatable portrayal of sibling relationships. The interactions between the characters are the driving force of the narrative, with minimal overarching plotlines, allowing the focus to remain on the charming and humorous moments that define their lives.