So... what's the secret behind Secret?

[immel]

Some people have already claimed that there's nothing secret about this album, and they are baffled by Ayu's choice of title.

Well, think about it. Would it be a secret if we knew about it already?

The answer, harsh as it might be, is no. It's okay though, don't suicide just yet.
If you still plan to, I know a couple of good bridges.

Will we ever know what the secret is? Who knows. We can but speculate.

So what, then, is the hidden message behind this title? What is this "missing" secret she's trying to tell us about?

Ayu is pregnant. Apart from that, you are free to come with your own conclusions.