Eh, without knowing their past I got "childhood friends" vibes until he shut her down once. Then she kept pushing and I got the impression they have history. Then when he started making an excuse, stopped, and switched to flat out denying her, it became pretty apparent that they were involved at one point. I don't know the context right now, but I can tell there's a reason.
Love the "im bus- no, no I don't think I want to." He was boutta give her an opening, maybe when he's not busy they could grab coffee or something, but he shut that down quick. Good man.
No, he was just trying to be polite at first. It's a Japanese thing...saying "no thank you" without actually saying it...then he changed his mind and was direct.