Rika, originally named Majo Rika, hails from the Witch World. Born from a rose in the Witch Queen's garden alongside her rival Majo Ruka, both were seen as potential future queens in infancy. Raised by the kind witch Majo Ririka, whom she calls "Mama Rika," Rika fostered a long-standing rivalry with Majo Ruka during their youth, frequently clashing in arguments and pranks.

Her witch form features dark green hair styled in large oval buns with a forehead curl, red eyes, and minor wrinkles. She wears a dark green one-piece outfit with a purple collar, a shawl-like cape lined in indigo, pink and purple striped gloves, gold loop earrings, and a signature purple crystal ball necklace. A curse triggered by a human discovering her identity transformed her into a witch frog: a green frog retaining her forehead curl, with button eyes, red lips, and often seen wearing a witch hat and shawl.

Personality-wise, Rika exhibits a grumpy, cantankerous, and easily irritable nature. She displays greed, a love for money, and a tendency for impulsive business schemes. Calculating and self-serving, she struggles to express vulnerable emotions honestly and rarely admits fault. Despite this harsh exterior, she harbors deep care for her witch apprentices, viewing them as daughters and offering genuine comfort during difficult times. Interactions with them gradually soften her, revealing kindness and a capacity to enjoy leisure.

As a witch, Rika commands strong magic, specializing in enchanting objects using strands of her hair. She retains most abilities even as a frog. Her fairy companion, Lala, shares a close bond with her; their teasing banter often aggravates Rika, though mutual care remains evident.

Rika's story begins operating the magic shop Maho-dou in the human world. Doremi Harukaze accidentally exposes her identity, triggering the curse. To reverse it, Rika makes Doremi her witch apprentice, tasked with passing nine witch tests. She later extends apprenticeships to Hazuki Fujiwara, Aiko Senoo, Pop Harukaze, Onpu Segawa, and Momoko Asuka as they uncover her secret or join the group.

Her rivalry with Majo Ruka intensifies over ownership of the Maho-dou in Misora City, which Rika wins. They eventually reconcile, becoming drinking companions and friendly associates in later years.

During the second season, Rika temporarily resides in the Witch World while the apprentices care for the magical baby Hana, born from the Witch Queen's rose. Rika acts as a secondary maternal figure to Hana, providing care in the apprentices' absence.

In the third season, Rika supports the apprentices running the Maho-dou transformed into a bakery as they prepare for patissier exams to become full-fledged witches. Her relationship with Momoko evolves from initial annoyance due to Momoko's clinginess to understanding after recognizing her resemblance to Momoko's late mentor, Majomonroe.

The film *Motto! Ojamajo Doremi: Secret of the Frog Stone* depicts Rika accompanying the apprentices to Fukuyama to investigate a local Edo-period legend of star-crossed lovers, further integrating her into their human-world experiences.

By the fourth season, Rika mentors the apprentices managing the Maho-dou as a crafts shop and assisting Hana, now aged into a sixth grader. She plays a role in resolving the crisis involving the former Witch Queen Majo Tourbillon.

In light novel sequels set years later, Rika, using the human name Makihatayama Rika, continues operating the Maho-dou. She serves as Hana's guardian while Hana prepares to become the next Witch Queen. Her relationships with the now-adult apprentices endure, reflecting a lasting familial bond.

Rika's background includes a failed attempt to become a Pureleine due to her greed. Her age is hinted to be at least 800 years during the series. The surname Makihatayama, used in the human world, derives from Japanese words meaning "winding," "machine/loom," and "mountain."