
Quick answer — Saori Seto voices Akiko in ItaKiss, Ayako Matsumoto in ItaKiss, Grayfia Lucifuge in High School DxD and 6 more characters.
Saori Seto voices Akiko (ItaKiss), Ayako Matsumoto (ItaKiss), Grayfia Lucifuge (High School DxD), Evergreen (FAIRY TAIL (2014) OVA), Sera Rokudou (Tokyo Majin), Sumire Amagasaki (I My Me! Strawberry Eggs), Kaoruko Mayuzumi (Infinite Stratos), Misa Kitagawa (Photo Kano) and 1 more.
Akiko is voiced in Japanese by Saori Seto.