Rider
"Well, yes, I am actually, how did you know?" she said with a sultry smile.
Then, she paused for a moment, as if reflecting upon his comment, before letting out a small giggle.
"Oh, I see, you thought...", she said, acting as if she'd just realised his misunderstanding, the sultry smile returning to her face. "No, my master isn't that kind of master."
With that, Rider paused for a moment, wondering how much information to give. She didn't want to scare him away, he seemed like he could be fun, but nor did she want to say anything that might turn him against her or, worse, against Sakura.
"Hmm, it's.. complicated to explain. But, basically, I protect her from harm, and she provides me with what I need to live. But, she's more like family to me, really, and I am to her. I would protect her even if I did not need her to provide for me, and she would provide for me even if she did not require protection."
Then, she pondered the last part of his statement.
"As for my name, well, I suppose she did give me it, in a way", Rider added with a giggle.
"As for why I was given that name, well, perhaps I'll show you later...", she finished, the sultry smile returning.
Of course, the statement had two meanings. She certainly intended to demonstrate her bike-riding skills, once she'd found the bike of her dreams. But, if he played his cards right, she would certainly consider demonstrating her riding skills in another manner....