I have known about Soushoku danshi but just now know about Otomen.
Actually I don't see any differences between these 2 concepts.
Maybe the only difference is their desires of sex??

草食男子[soushoku danshi]
[オトメン（乙男）Otomen](http://bangin.wordpress.com/2007/07/11/%E3%82%AA%E3%83%88%E3%83%A1%E3%83%B3%EF%BC%88%E4%B9%99%E7%94%B7%EF%BC%89otomen//)

[img]http://i799.photobucket.com/albums/yy272/flower_of_life/Indigo_Blue_Chapter_10_148-1.jpg[/img]