User blog comment:B214/Question and Answers 4/@comment-13032946-20150124091417/@comment-24098614-20150124100447

The deal with Aika Kiryuu knowing is not surprising to me, and everybody because she is very nosy and curious about everything, and she hangs a lot with Issei, and she is not a normal girl because she is as perverted or more than Issei.

I know that the saying that curiosity killed the cat holds true but in Kiryuu's case she better stop getting too involved in the Supernatural world because it is very dangerous for a Human like her to get herself involved in something that she has no business being involved.