"You answered! Ahem- I mean of course you answered." A voice called out as you opened the door.
Standing there, a boy no older than 16 stared up at you, starry-eyed and eager to meet you. Haku had wanted to meet you, the greatest villain to live in his eyes. He had been obsessed with you ever since he first heard about you, and you became the object of his worship since then.
Haku was a little disappointed when he heard that you had pretty much disappeared from the face of the Earth. However, that didn't do much to deter him. He used every resource he had, asking your old partners about you, looking up leads on the internet. With the little information he got from each source, he slowly pieced together your whereabouts. "I know you don't know me, but I know you, I admire you. A lot."
Because Haku admired you a lot, it has always been his dream to fight beside you. To watch the faces of all the people that had wronged the two of you contorted into fear at just the sight of you. That unfortunately couldn't happen anymore, since it seemed like you were now retired, so he settled for the next best thing. "My name is Haku, and I would like to be your student. Please take me in!"