Guy got ready for their spar, Sasuke also started to remove the weight he was wearing. After removing the weights then opening his sharingan he took the battle stance. Guy was surprised by Sasuke's action, and after seeing his sharingan he was further shocked;
'This boy is really giving his everything to his training, he has started weight training at such a young age and how did he awaken a matured sharingan at such a young age. He really is a genius of Uchiha clan. I will give him proper guidance for weight training and appropriate diet for his age after the spar session.'
"So you have awaken your sharingan at such a young age, your youth is burning brighter and brighter Sasuke. Now attack me with everything you have got."
With that they started exchanging moves, Guy was not attacking, he was just hitting any opening he saw in his taijutsu style. He was just pointing out the shortcoming of his fighting style. With the help of sharingan Sasuke was gaining a great insight by Guy's action. The fight lasted for two minutes, in two minutes Sasuke was exhausted. If a third person was watching this spar they would observe that Guy did not move much while Sasuke was all over the places. Sasuke gave everything to this fight, he tried very hard to at least make one of his attack connect with Guy so that Guy would be impressed with him but he never succeded. And every time Guy makes a move, Sasuke gets knock down. This fight was more insightful for Sasuke than training for 3 month.
After getting destroyed in the fight, Sasuke bowed to Guy and said;
"Thank you for guiding me, I learned more in this fight than 2 years in academy and last 6 months of training the Uchiha clan taijutsu. So what level do you think my taijutsu is currently?"
Guy thought for a moment before speaking;
"You did very well Sasuke, power of your youth cannot be matched by any genin, your youth shines brighter than many chunin. If you show this kind of determination everyday then I will guide you so that your youth will be brighter than anyone else in entire shinobi world."
"It would be great honour for me to learn from you, may I call you Guy sensei?"
Guy did not expect that Sasuke would be this humble. He thought he would be an arrogant brat especially with his 3 tomoe sharingan, he is not even 9 years old. His previous experience with uchiha clan member showed him that they are extremely arrogant, and guys with a mature sharingan thinks that everyone else are beneath them. Guy was touched by the humble nature of this uchiha kid, so he decided to train him in his free time. He finally spoke;
"Yes Sasuke you can call me sensei, the power of your youth has convince me to train you, I will meet you near training ground 3 every day, if I am not on a mission. So Sasuke lets train together and burn our youth to next level."
"Thank you Guy sensei, I will train hard and make you proud." Sasuke said happily, he finally found a sensei who is the strongest taijutsu master in the world. With his guidance he taijutsu training will always be in the right track.
"Sasuke how about wearing this youthful green suit, it is specially designed for the training we are about to go through. With this suit your youth will shine even brighter." Said Guy, taking out a green one piece track suit.
Sasuke got nervous and start sweating; 'I should have known if I become his disciple he will try to make me wear this ridiculous suit. Does he always carry few of these suits with himself?' He quickly came up with a excuse, and said;
"You see Guy sensei, these are the clothes with my clan symbol on it, these clothes give me the identity as the last uchiha so I cannot wear anything else."
"Ok then, it is really unfortunate that you cannot wear this but to compensate we will do more training. Now Sasuke follow me to this youthful journey." Said Guy.
Sasuke training continues and six months pass. Now he has good chakra control, he can walk, run and also fight on water like he is on land. He has also in the final step of mastering the rasengan. He was 9 years old now, and last week he snuck into the library section where academy students were not allowed. He was not looking for ninjutsu as he can always copy it with help of his sharingan by spying on two jonin sparring in the training ground. What he was looking for was scrolls on fuinjutsu. He was not looking for some high level forbidden fuinjutsu as he knew he is not trained enough to venture those places where they were stored, what he was looking for were daily necessity seals like storage and paper bomb etc. These kind of seals can be bought in ninja supply store but the fuinjutsu related to their manufacture were not available for academy students like him. In his expedition he put three chunin in genjutsu and also erase the memory of their encounter. He was very satisfied with the level of his genjutsu.
There was a knock on his door, when he open the door he saw a person with his face covered in a mask with gravity defying silver hair. Sasuke was confused why suddenly Kakashi was visiting him. He looked at Kakashi with confusion in his eyes and asked him;
"How can I help you?"
Kakashi was surprised that Sasuke can recognize him but then again Sasuke knew he had sharingan and also he was training with Guy so recognizing him is not unexpected.
"I heard that you wanted to learn Hatake clan kenjutsu." Kakashi answered him lazily.
Sasuke then remember the conversation he had with Hokage one year ago. 'So he is answering for that trade I offer 1 year ago. It took him 1 year to decide, he should not be called copy ninja instead he should be called late ninja Kakashi.' Thought Sasuke then he replied to him;
"Yes I remember, so have you come here to teach me your clan's kenjutsu?"
"No, I don't use swords neither am I train in my clan's kenjutsu but I can let you see the scroll of my clan's technique for 5 minutes"
"Fine I am ok with that." With that Sasuke finally got his hands on kenjutsu technique.