i remember reading someone writing about hirakawa daisuke (seiyuu of katsuya of both seme and uke katsuya). she was going all crazy about seme katsuya's voice being all sexy and so on, that hirakawa daisuke should use more of his seme voice than the uke version.

if you listen to the sample voice, you wouldn't even think they are by the same person. they sounds so different. on top of it, the seiyuu himself sounds different when speaking normally too. most male seiyuus don't sounds different at all on stage and off stage. let's just put it as hirakawa is a very versatile seiyuu.

ok, it turn out that hira-chan was active as uke in BL dramas. (thanks, samantha for the correction) i am not that into BL dramas. actually, i was not even that into BL or yaoi manga until a year ago. then i only started on BL game or dramas cd a month ago. guess i missed out a lot. (why does all uke sound the same in H scenes? are they are all imitating the same person. do people really make so much sounds in H scenes?)

as for recently, hira chan is more active in his seme voice for these few years. i wonder why? late puberty? however, he still inter-change a lot, depending on his character's personality and situation. he used the seme voice for this demon who stand and has a figure of a woman but a personality of the king of hell (or it seems to) in 断罪のマリア THE EXORCISM OF MARIA. (this game looks really good too. seems like we are in for a blood bath too. wohoo~~~no, he look like tomato soup is poured over his head.) sorry for this lame joke but in sigma harmonics, tomato soup is an important clue. 

this is how hirakawa sounds normally. like katsuya with a sore throat.
http://quinrose.com/game/crimson/img/c_v/s_ja/justin.mp3