Bruja Rika is the Spanish-language adaptation name for the character known in Japanese as Majo Rika, a central figure in the Ojamajo Doremi franchise. She is initially introduced as the original owner of the Maho-dou, a magic shop located in the human world. Her secret life as a witch is accidentally discovered by a young girl named Doremi Harukaze, which triggers an ancient and powerful curse. This curse forces any witch whose identity is exposed by a human to transform into a magical frog-like creature known as a witch frog. To break the spell and return to her original form, Bruja Rika is compelled to make Doremi her apprentice, tasking her with training to become a full-fledged witch.

Bruja Rika possesses a very strong and often abrasive personality. She is known for having a hair-trigger temper and frequently shouts at her young apprentices, with a common catchphrase being a sharp "You idiot!" She is a deadpan snarker, constantly making sarcastic remarks, especially towards the girls under her tutelage. Her demeanor is that of a sink-or-swim mentor who has little patience for mistakes, preferring to point out what the girls do wrong rather than praising their successes. Despite this harsh exterior and her initial portrayal as a fair-weather mentor who is primarily focused on lifting her own curse, she demonstrates a genuine, hidden care for the girls. She is also notably fond of money and can be motivated by greed, which sometimes leads to comedic situations.

The character's primary motivation throughout the first season is to have Doremi and the subsequent apprentices pass their nine witch tests and become full witches. Only then would they have enough magical power to reverse the curse and restore her to her humanoid form. As the series progresses into later seasons, her role evolves significantly. After her initial curse is resolved, she departs for the Witch World. However, she remains deeply connected to the human girls, especially after the birth of Hana, a magical baby and future Witch Queen candidate. Bound by Witch World law, Rika facilitates the return of Doremi and her friends as apprentices to help raise Hana. Over time, Bruja Rika transitions from a figure singularly focused on her own predicament to a dedicated mentor and custodian of Witch World traditions. By the final season, her development is such that she acts as a responsible guardian of magical customs, personally returning Hana to the Witch World after the protagonists make their final choice to relinquish their magic permanently.

Her key relationships are primarily with her apprentices. While she often clashes with Doremi due to the girl's clumsiness and impulsiveness, she shares a deep bond with all the main girls, including Hazuki, Aiko, Onpu, and Pop. In a moment of vulnerability, she admits that she views them as being like daughters to her. She also has a notable sibling rivalry with her twin sister, Majo Ruka, who acts as an eternal rival. Bruja Rika's development is marked by this shift from selfishness to selflessness. Early friction with the girls over her perceived laziness and greed gives way to a deeper commitment to their growth and well-being. Her involvement in critical events, such as mediating conflicts between the Witch and Wizard Worlds and supporting the girls through Hana's various health crises, illustrates this profound change.

In terms of abilities, Bruja Rika is a skilled witch with access to a wide range of magical powers. However, for much of the first season, her abilities are severely limited by the witch frog curse, which traps her in a small, green, amphibian-like form. In this state, she is incapable of performing advanced magic and is completely dependent on her apprentices. In her original humanoid form, she has pointed ears, a common trait among witches, and rides a flying broomstick. Her magical knowledge is extensive, allowing her to oversee the training of multiple apprentices and navigate the complex laws and traditions of the Witch World.