No this theory doesn't have anything to do with the title character. But with Kyon's little sister, and Asahina Mikuru

This theory might be wrong and full of bull s**t but who knows? I could be right. Though I seriously don't think so.

The theory is simple. Mikuru is Kyon's sister from the future. Why I thought of that.

They look a lot a alike

1. The eyes look almost the same, well at least if you compaire the right pictures together.

2. Hair look simlier.

3. Faces.

I can seriously can think of his sister looking like Mikuru when she grows up.