Ask John: Why do Female Seiyuu Perform Male Roles?

Question:
Why do some anime characters who are men have their voices done by women?

Answer:
Female seiyuu playing male anime characters is not at all uncommon.

Ai Orikasa (Quatre of Gundam Wing)
Megumi Hayashibara (Umino Hiroshi of Queen Emeraldas)
Nozawa Masako (Dragonball’s Goku, Gohan and Goten, Tetsuro of Galaxy Express 999, Kitaro of Ge Ge Ge no Kitaro)
Suzukaze Mayo (Himura Kenshin of Rurouni Kenshin)
Megumi Ogata (Yukito of Card Captor Sakura, Shinji in Evangelion)
Tanaka Mayumi (Dragonball’s Kurillin and Yajirobe)

have all portrayed male characters in anime before, just to name a few. I don’t know very much about the Japanese seiyuu business, but my guess would be simply that because the anime industry in Japan places such a heavy importance on matching just the right voice to each anime character portrayed on screen, gender is not considered when anime producers cast for roles. Presumably, in these and other cases, female voice actors were simply best able to match the vocal tone that the director had in mind for a particular character.