
Quick answer — Rika Morinaga voices Matsuri Saegusa in Kamichu!, Mamiina in Simoun, Souseiseki in Rozen Maiden and 12 more characters.
Rika Morinaga voices Matsuri Saegusa (Kamichu!), Mamiina (Simoun), Souseiseki (Rozen Maiden), Ren Kannagi (Kaze no Stigma), Yumie Hanamura (Hell Girl: Two Mirrors), Makoto (Minami-ke), Mawari Zenigata (My Bride is a Mermaid), Kana Ikeda (Saki) and 7 more.
Matsuri Saegusa is voiced in Japanese by Rika Morinaga.