Nicole Segawa, known in the original Japanese version as Onpu Segawa, is one of the main characters in the anime Ojamajo Doremi Sharp, appearing from the second half of the first season onward. She is a child idol who works as a singer, actress, and host of her own morning radio show, which earns her a large fanbase, especially among boys. Onpu is also a witch apprentice, initially trained under Majoruka, a rival to Majorika. She first transfers into the same elementary school as Doremi, Hazuki, and Aiko, and initially behaves in a disdainful, selfish, and spoiled manner. She uses forbidden magic to influence people’s memories in order to cheat during an audition, which reveals her identity as a witch to the other apprentices. Despite her cold and enigmatic facade, Onpu gradually reforms her ways after spending time with the group, revealing a kind, selfless, and hardworking nature. Her motivations are partly driven by her mother, who was a failed idol herself and now acts as Onpu’s agent, pushing her toward fame. Onpu’s father works as a train driver and is rarely present, leaving her to bear the pressure of her career alone.

Within the story, Onpu serves as a rival-turned-ally, eventually becoming a close friend and core member of the witch apprentice group. She develops a particularly strong bond with Doremi, whom she enjoys teasing but also credits with helping her break down the emotional walls she had built. She also shows affectionate feelings toward Tooru, a member of the wizard group FLAT4, though she has no definitive romantic interest. Her character arc is marked by significant growth: she begins by relying on her idol status and forbidden magic to get ahead, but later learns the value of genuine friendship and sacrifice. In a pivotal moment, her overuse of memory‑altering magic causes her to fall into an eternal sleep, and the other apprentices give up their magical powers to save her. In subsequent seasons, she joins the others under Majorika to help raise the magical baby Hana, and she continues to mature into a more open and dependable person.

Onpu’s notable abilities include her witch magic, which she activates with incantations such as “Pururun purun famifami faa” for general spells and “Puritii wiichi Onpu-chi” for transformation. She also uses forbidden magic to erase or alter people’s memories, a skill that proves both dangerous and crucial to the plot. As an idol, she excels in singing, acting, and public performance, and she plays the flute. Her favorite color is purple, and her fairy companion is named Roro (or Lolo in some dubs).