Arale Norimaki is a humanoid robot who serves as the main character of her series. She was built by the inventor Senbei Norimaki and has the physical appearance of a young girl. Her name is a pun on arare, a type of bite-sized rice cracker.

Arale is characterized by her naive, energetic, and cheerful disposition combined with a profound lack of common sense. Her actions are driven by a simple and innocent curiosity about the world, leading to humorous situations as she misunderstands basic human customs. Despite her childlike personality, she possesses unbelievable superhuman strength and can perform feats far beyond any normal human. She is also nearsighted and must wear glasses, which became a defining visual trademark. Her creator, Senbei, tries to pass her off as a normal human girl to the residents of Penguin Village, a task made difficult by her frequent displays of superhuman ability. Arale has several unique verbal expressions, including N'cha as a greeting, Bye'cha for goodbye, Hoyoyo to express bewilderment, and a shout of Kiiin when she runs at high speeds.

In the story, Arale is central to the humorous exploration of life in Penguin Village and the adventures that arise from Senbei's inventions. Her key relationships are primarily within her family. Senbei Norimaki is her creator and acts as her father figure, while Midori Norimaki becomes her stepmother. She has a younger brother named Turbo and a sister named Nitro. The family also includes Gatchan, a small winged creature that hatched from an egg Arale and Senbei discovered while traveling to the past. Arale is also stated to have a husband named Obotchaman. Her role extends beyond her own series, as she has made significant crossover appearances in the Dragon Ball franchise, where her pure heart allows her to ride the Kinto'un cloud.

Arale possesses a range of notable abilities that reflect her nature as a powerful gag manga character. Her most famous techniques include the Chikyūwari, or Earth Chop, which can split the ground, and the N'chahō, or N'cha Cannon, a powerful beam fired from her mouth. She can run at incredible speeds and has demonstrated the ability to travel to the moon and other planets with ease. Her strength is essentially limitless within the context of her comedic world, allowing her to perform impossible feats such as cracking the Earth or the Sun. She is also capable of breaking the fourth wall and has shown an ability to transform, such as mimicking a Super Saiyan. While she is a robot, her design includes human-like qualities and limitations; for instance, her energy supply can be drained if she uses her N'cha Cannon too frequently.