Who knows really, there are many possible theories :
1. Maybe he didn't know/care/bother, he only got to know her as they worked together.
2. Maybe he was informed of her by his manager when he was casted to work with her. And then he got to her know as they worked together.
3. Maybe he didn't bother looking into her before he met her. But after he met her, when he got some alone time, he googled her.
4. Maybe he googled her before they met and that's how he managed to wooh her!
5. Maybe one of his friends introduced them and that's how he got to work with her.
6. Maybe Ayu discovered him and she was the one that persued him first.
I like speculating
