Yugi listened attentively as Djinn explained her history, and how this all came to be. He was surprised that someone had managed to do such a feat, noticing that what his Grandpa told him about the Puzzle was true and that what he carried contained magic, in a sense anyway. He guessed that it still did for having Djinn be awoken by being in the presence of it. At least so he thought. While he had listened to her story, he at times looked the Millennium Puzzle though back to her as she had come over to sit on his bed by the end of the story. He had to admit this was quite a bit to take in, but she cleared up alot of questions, even warning him of several evils out there and that since he is the possessor of the Millennium Puzzle. She was now his protector and he alone could see her which Yugi thought was a little of a let down. He wished his friends could see her as he was seeing her now. 

But to know that she was asking his permission basically was a little of a shock, but seemed to understand. How could he say no? She had told him her story, how the puzzle was her life source and was the protector of it, Yugi couldn't do such a thing. "Well, after hearing your story, and to know a bit more about you and the Millennium Puzzle. I'm not gonna turn you away. I accept. I've never met a Duel Monster Spirit before. But like grandpa I believe cards and a deck especially have a heart." Yugi told her with big smile. "Your a proving his belief in that."