Nami Miyahara is the voice actress of both Momoko Asuka and Masaru Yada in Ojamajo Doremi. She was born on Jan 24th 1978 in Tokyo.
Shouko Yamanobe: Mamotte Shugogetten
Yukkutakku: Yume no Crayon Oukoku
Irina Goinov: St. Luminous Mission High School
Jurika Jinno: Magic User's Club
Yada Masaru, Momoko Asuka: Ojamajo Doremi
Paula: PaRappa the Rapper TV Series
Wallace: Digimon Adventure 2, also voiced him in Drama CD's
Popo: Kouchuu Ouja Mushiking ~Mori no Tami no Densetsu~
Miyako/Bubbles: Powerpuff Girls Z
Lyuze, Janice (Singing voice): Cassern Sins
Yuuya Kogure: Inazuma Eleven
Utasha: Umi Monogatari ~Anata ga Ite Kureta Koto~
Sludge: Astro Boy
Aisha Aldola: So Ra No Wa To
Akari Tsukumo: Yu-Gi-Oh! Zexal
Popo: Kouchuu Ouja Mishiking ~Mori no Tami no Densetsu~
The reason she does english voices so well and clear is because during her middle school years she and her family had moved to Austria for some time.
Both her and Rumi Shishido have worked together on Ojamajo Doremi, Powerpuff Girls Z (as Miyako/Bubbles, and Sakurako/Sedusa, respectively) and Kouchuu Ouja Mishiking ~Mori no Tami no Densetsu~ (as Popo and Pam respectively).
Both her and Sawa Ishige have worked on Magic User's club.