Why Momochi Zabuza had taken on another young charge still baffled him, and probably everyone he came across. A fearsome swordsman of questionable repute flanked always by a ten-year-old girl, and a thirteen-year old boy. What an absurd picture he must make these days. He reassured himself once again that in the long run things would work out. He already knew that Haku was a prodigy, could tell from the moment he lay eyes on the frail effeminate child that he was a rare and precious talent. And Aya, though slow to start, was coming along nicely too. One day he knew that even he himself, The Devil of the Mists, would be outmatched in the arts of subtlety and quiet deadliness by this tiny nomad girl. He would teach these two everything he knew so that he could posess the most powerful weapons one could wield.

So he trained them vigorously. Day-in, day out. It was gruelling work, and Zabuza was neither a patient nor caring tutor. Yet he found his students adept, and they flourished under his hard brand of teaching, though both had very different reasons as to why.

For Haku it was simple gratitude. He would work himself long after any other would have been well beyond their own limit, powered simply by the sheer dedication to the mentor who had rescued him from certain death at the hands of fellow Mist-Villagers. Haku loved Zabuza fiercely, and had once swore solemnly to Aya that if it came to it, he would gladly sacrifice himself to save the swordsman.
'He's my older brother, the father that mine should have been but wasn't, my teacher, and my savior.' He had said vehemently upon being asked why he worked so hard. 'My life would have been over so long ago if it weren't for him, and I can't go happily unless I return the favour. When a person has someone important to protect, that's when they become truly strong'
Aya had nodded and said nothing, not quite grasping the feelings behind Haku's words.

For her it was simply means to an end, as was everything she had done since leaving the destroyed camp over a month ago. Young and inexperienced as she was, she'd found a focus within herself that she never knew she had. Now she had a cause, a purpose. A great mission that overshadowed everything. Find her family, and destroy those who had taken them away from her. Her selfish little heart longed to regain what was rightfully hers. Every ninja had their own purpose, their own drive, And this was Aya's, and she would do anything to fulfil it. Time was a non-factor to her, she would wait patiently until she was skilled enough to strike them at their very core, wherever that was.

Her only clue still being the music-note forehead protector. She had presented it to a surprised Zabuza and Haku mere minutes after encountering them, asking boldly if they knew anything about where it had come from and foolishly proclaiming that she would single-handedly hunt down and annihalate anyone with that symbol anywhere on their person.

She simply couldn't comprehend why the small boy's eyes lit up with guilty amusement, and the terrifying man towering over her had snorted derisively. There was nothing funny about what she had said, she was sure, and yet there they were, standing before her laughing. Bafflement suddenly gave way to a burning anger. Aya clenched her tiny fists, blinking back tears of rage and embarassment. They were making fun of her! They were making fun of her cause, her great mission! She couldn't lift her eyes from the ground lest they see the tears forming.

'Go away, little girl.' The man growled, suddenly tiring of bullying such a small child. 'Look at you, standing there crying like a brat who lost her kitten. Run home to your mummy. You couldn't hurt a fly, let alone take on a whole village by yourself.'

Aya couldn't do anything else but turn tail and flee, humiliation flushing her pale face scarlet.

Zabuza shook his head, looking to Haku, who still wore a guilty expression.
'Kid, you're lucky you're with me. You'll never end up cowardly and weak like her if I'm training you.' 'I kind of feel sorry for her, Zabuza-san.' Haku replied, watching Aya's retreating back. 'She doesn't seem to know very much about the world. And she's only very little and seems quite bent on something that she obviously can't do'
'That's not our problem kid. She talks big, but you know as well as I do she's soft'
'Suppose. I still feel sorry for her though'
'Forget about it. We gotta move on, anyway. She might squeal to her parents about us, and I don't particularly feel like being hunted down today'
With that, they turned and moved off.

Aya hadn't run very far before the helpless rage she was feeling manifested itself into something she had never felt before. Her whole body shook with with it so strongly that she had to stop for a second and catch her breath. She looked over her shoulder to see if the pair that had laughed at her were still watching. They had turned around and almost autonomously she seized her chance to strike.

She made no noise as she closed the gap between herself and the two, not even the barely discernable whistle of the obsidian claws being unsheathed gave her away. After all, silence had always been her talent. And so good was she at being silent that Zabuza only noticed that Aya was there when she landed with a tiny thump right in front of him, eyes blazing, wearing a smile that looked almost unholy on such a small child.
'Never turn your back to me.' She said, her voice fairly dripping with smug triumph. 'Or next time you'll need stitches.'

Zabuza couldn't help but show his surprise when his hand left his back and found it soaked with blood. The claws were so sharp he hadn't felt them rip into his flesh as Aya had launched herself over his considerable height. Maybe there was hope for the little wretch after all, and being the opportunist he was, Zabuza couldn't resist the idea of adding another tool to his collection.

And so Aya joined the infamous Devil of the Mist and his young protegee.