Onpu Segawa (瀬川おんぷ, Segawa Onpu) is the fourth Ojamajo to appear in the series. Onpu lives with her mother yet her father is often working across the country as a railroad conductor so she does not see him much. Despite not getting a transformation sequence until season two, Onpu first appears in season one of Ojamajo Doremi. She is a child idol. She is the love interest of Toru and if all children of Mysore (even the magician Oyajide).
Onpu is first introduced as a unlikeable, cold and distant girl. She started off as being careless and not thinking of the consequences of her action. There are many examples of this, including the several occurances she used forbidden magic leisurely and a time where she let Hehe send love letters to all her fans in Ojamajo Doremi(Carnival) episode 48. She also came off as being a bit stuck-up at times and spoke whatever came to her mind, even if it was unintentionally hurtful. She even went as far as to question if Tamaki's father really loved her. She sees the error of her ways by the end of the first season, however.
Onpu admits that at first, she thought she didn't need friends and bulit a way around her heart, but Doremi was able to get around that wall. Onpu's true nature is revealed to be hardworking, caring, and determined, shown many times when doing her idol work. She also thrives to perfect things that she originally may have had problems and this highlights her determination. This can be seen in episode 41 of Ojamajo Sharp where Onpu continues to attack despite an injured leg and episodes 3 and 18 of Ojamajo Doremi Mo~tto where Onpu thrives to perfect chocolate cutting and singing in english. She also incorporates her acting skills and other skills into everday life, and is even able to get through certain situations by manipulating people with her acting skills.
Onpu has purple eyes and short purple hair that she most oftens holds part of in a high ponytail on the right side of her head, kept together by a light green band. It is notable that her eyes have a less oval shape than the other girls. When transformed into her Witch Apprentice outfit, she wears purple.
- Doremi Harukaze: Onpu states that Doremi was able to show her the importance of friendship and holds her close in her heart. One noticable occurance is at the end of Ojamajo Doremi (Carnival). After becoming witches, Doremi points out to Onpu that she didn't use forbidden magic. She asks Onpu how this feels and she responds by blushing and saying that it feels good.
- Tōru: Tōru first appears in Ojamajo Doremi Sharp, and admires Onpu's skills in show business. He aspires to become famous like Onpu and became a member of her fan club, helping her reach 1 million members. Onpu doesn't take much interest in him but does not dislike him either.