Kakashi and Obito
Even though Obito is an Uchiha, his skill level seems to pale in comparison to Kakashi.
This is maybe one of the reasons why Obito and Kakashi don’t get along. Kakashi's
strictness for following the rules and his coldness annoy Obito and this usually leads
to Obito exploding angrily. Even though they argue, Obito has a great amount of respect
for Kakashi and wants to be friends with him, only Kakashi always pushes him away.
Obito and Kakashi are also rivals, Obito feels that once he activates his Sharingan,
he’ll be able to surpass Kakashi and finally see himself as worthy of the Uchiha name.
Later on, Obito gains an understanding of Kakashi and the reason behind his strictness
for following the rules when Minato tells him about Sakumo Hatake, Kakashi’s father.
Later the two become best friends, even if their friendship is short-lived.