Ken is straight.
I've just finished Ken's route so far, so potential spoilers...
This confuses me somewhat. He's displayed interest in Grey and even asked if they should kiss, showing at least part of him wants to. Do you mean he's straight because that's what he identifies as regardless of lables people put on him, or his behaviour? Or he's straight regardless and would never want to persue a relationship with another man? I understand Ken overcoming his homophobia is a large part of his character development, and that it doesn't always have to be internalised.
Regardless, the character writing is brilliant, and I love the horror aspects!
Wait, he is? There's a few lines in the latest build that give the impression that he might have growing feelings for Grey...I'm not going to argue with the actual creator for the VN, but I do find that a little confusing.
Unless you mean "Ken certainly believes he's straight," In which case I certainly understand.