Sasuke Uchiha is a rival of the main character Naruto, in the series "Naruto" In the first part of the series, Sasuke constantly buttsheads with Naruto, too compete with him and try to prove that he himself is better. Sasuke wants revenge against his brother Itacthi. So he left the Leaf Village to learn new jutsu and become stronger by Orochimaru. Later in the series, Naruto always looks back on his former teammate Sasuke. He knows he has to become stronger in order to get Sasuke back, so that makes Naruto try twice ashard. As you can see, sasuke is a huge influential character on the series, even though he is not present in alot of episodes later in anime.

He is a well thought out character and well drawn.