Edwardsan: I think you could pass, but try out some crossplay makeup. (Especially eyebrows. Thin eyebrows are girly. )
It helps to play around with makeup AND facial expressions!
rinjixrocket: Wow. I can see you being Yoite very easily.
And with the right makeup, L should be no problem. However, FtM makeup won't hurt. Just make sure to make it light, because L and Yoite are very very pale.
Thank you for cosplaying Yoite, by the way.
He's my favorite character ever. (Cosplaying him was a bit warm, though. ^__^')
Sutie- I can see the resemblence there. ;D Hmmm. Definitly thicken/darken your eyebrows with small strokes... and general FtM makeup should help. With that, I think you'll be a great Koga.