[infectus]

Originally Posted by Draugur

I think RandomAvatarFan is right. It's just a graphic way to express that someone is dangerous or mad, or the character from whose point of view the story is told thinks the person is scary or crazy. I don't think there is a strict rule about it as you might be thinking.

Spoiler:

But we can't see keiichi's "cat" eyes in the VN. We just know because Rena and Mion says it.