Naruto & Sasuke
Naruto and Sasuke’s rivalry started early on shonan Series. In the beginning and even before the original Naruto Series started. It started by Naruto saying he could do what Sasuke just did but he couldn’t. so Naruto has declared himself as Sasuke rival and later Sasuke wanted to fight Naruto however it got bad for Sasuke ever since the Chunin Exams. He saw Naruto surpassing him and wanted to fight Naruto so badly. So he learned a jutsu called Chidori from his teacher, Kakakshi Hatake. And Naruto learned rasangan from his master Jiraiya. Their rivalry kept on going throughout the whole series. Naruto was trying to keep up and get stronger than Sasuke. After he defeated Pain the leader of Akatsuki their rivalry was getting stronger. By the time the 4th Great Ninja War started they became equal in terms of power and strength.
Hashirama & Madara
Ever since Hashirama and Madara met at the river skipping stones during war they became friends. Back in the Senju clan, a funeral for the fallen ninjas including Hashirama's younger brother, Kawarama. Hashirama has disapproval to his father that children shouldn’t participate in war but his father punches Hashirama. Then later Hashirama other younger brother Itama who also got killed by the Uchiha clan. Hashirama only has one sibling left named Tobirama. Madara understood what Hashirama feeling because like him Madara only has one sibling left, Izuna. Madara and Hashirama had a dream that they would build a village where everyone would get along with each other even if they are from different clans. However, their friendship did not last long because Tobirama discovered and told Butsuma that his son had been meeting with Madara who is an Uchiha. He ordered Hashirama to use his meetings with Madara to spy on him and, if necessary, to kill him. Butsuma gave Hashirama two choices: either gather intelligence on Madara and report to them or else he will be seen as a traitor for his actions. Hashirama accepted this mission but he instead warned Madara. Later as they grew up Hashirama was forced to battle his close friend Madara many times before they eventually became the leaders of their clans. The two Uchiha brothers fought the two Senju brothers, Tobirama was able to wounded Izuna Uchiha during their fierce battle. As Hashirama once again tries call truce between two clans, Izuna told his brother not to accept their truce and so they retreated, leaving the other remaining Uchiha to surrender. Later on Izuna has died from his wounds but Madara took his eyes and transplanted into his own eyes, which gave him Eternal Mangekyō Sharingan. And later Madara once again battled Hashirama. He has told them that Izuna had died due to his injuries that he got from Tobirama and had left him his eyes to continue protecting the clan. He revealed that he had acquired the Eternal Mangekyō Sharingan, but nonetheless, after a day-long battle, Madara was finally defeated. As Tobirama going to finish of Madara, he was stopped by his brother who still wanted to seek peace. By sparing Madara and the other Uchiha, Hashirama and Madara was able to achieve their dream.
Obito & Kakashi
Ever since Rin died Obito became angry and with his anger he ended up killing the ninja without showing mercy and left to reform the group of rogue ninja from every villages to create Infinite Tsukuyomi which leads to the Fourth Shinobi World War. During the war he has a change of heart thank to Naruto, so team Minato has been reborn, with Obito, Kakashi, and a reincarnated Minato and joined forces to save the world from Madara Uchiha and later Kaguya Ōtsutsuki aka Rabbid Goddes. After Obito death, he was able to meet Rin before he enters the Pure Land, and from her words of encouragement Obito's spirit briefly returns to the living plane to let Kakashi borrow his powers, so Kakashi could help team 7 to defeat Kaguya.
Sakura & Ino
Ever since they met Sasuke, Sakura and Ino turn their friendship into rival for Sasuke's affections and rivals in general, turning practically everything, they do into a competition and kept one-up each other. They kept on arguing whenever they're see each other, and they often refer to each other by derogatory names such as "Forehead Girl or Billboard Brow" and for Sakura and "Ino-pig" for Ino.
Aside from them being rival and competing with each other, they are good friends because Sakura was able to gain self-confidence thank to Ino. Ino was able to protect to Sakura from the bullies when they were at young age.
