
Quick answer — Mai Aizawa voices Mio Naganohara in Nichijou - My Ordinary Life, Kameko in DENKI-GAI, Yumemi Hidaka in Sora wo Miageru Shoujo no Hitomi ni Utsuru Sekai and 14 more characters.
Mai Aizawa voices Mio Naganohara (Nichijou - My Ordinary Life), Kameko (DENKI-GAI), Yumemi Hidaka (Sora wo Miageru Shoujo no Hitomi ni Utsuru Sekai), Neris Filiam (Shining Hearts), Ayumi Kuramoto (SKET Dance), Rie Nishina (Clannad), Ayame Jinguuji (Ga-Rei-Zero), Ayano Minegishi (Lucky☆Star) and 9 more.
Mio Naganohara is voiced in Japanese by Mai Aizawa.