And there's another one right there, folks. Lol. But really, rival/second main character either just ends up with side character with a heads-up or in a surprise manner.
Well that was because Akira introduced a new half saiyan, it was sudden so he had to make trunks exist at least for those events to have taken place.
But yeah there is a lot for Naruto and Obito in terms of the likeness, they are opposites but have the same ideals. Obito is basically just everything Naruto would have been if he gave into his darker views like Sasuke. Its just as Naruto said, he or Sasuke could have had reversed roles. Sasuke could have likewise seen a better way then revenge earlier as he once said to Naruto he almost forgot about revenge completely and started to see team 7 as a new family but ultimately chose revenge. Even then they both could have gone a dark path or a lighter one. As it is though, Naruto on his light path experienced everything Sasuke did but Naruto chose the high road, the better one, willing to forgive. This is why he spared Nagato, begged Ay to remove the kill order on Sasuke, and now trying to find a way to resolve the problems of the shinobi world and Sasuke's hate. Even more so, the kage fight, Naruto knows the reasons as Itachi told him, but its always been more about being selfless and trusting to others than simply gaining it by power.
Kinda going over both this and the pairing debates, the ideal of Naruto is that he just wanted hokage and respect at first but went about it the wrong way. Naruto eventually met Iruka and team 7, putting the hate behind him. Even if he was the butt of every mistake early on for team 7, it was better than being alone all the time. Yet Naruto's loneliness forged his will to never give up. This kept him moving on, eventually earning the respect and friendship of Sakura, Sasuke, Kakashi, and eventually everyone else. Naruto's ideal for hokage soon changed to be more like the will of fire. As in real life respect is not something deserved, you don't get it because you demand or command it, not even earned in cases too, respect is something created because one becomes mutual with others in forms of acceptance. Naruto worked hard for the respect he always dreamed of and it came as he grew. This same philosophy can be the same for the whole pairing ordeal, this is why I don't like the whole "Hinata deserves Naruto more" ordeal. In fact not only does Hinata not deserve Naruto, Naruto does not deserve Sakura, as Sakura does not deserve Sasuke. The whole ordeal with love is that its created and built, not something to be earned. Feelings are not built, they are not an object that can be possessed or earned, feelings like respect and love are things that are developed and carried by those who share mutual views and outlooks that make both experience more pleasurable events and relations. In this case, Naruto does not simply earn Sasuke's respect or Sakura's love, he builds those feelings for them and as they return other feelings to him, this determines if Sasuke will in turn carry the respect Naruto has for him and if Sakura carries the love he has for her. We can say Sakura likes Naruto a lot, she is great friends with him, yet that love she carries can start to develop into something more. Sasuke on the other hand, it becomes a matter if Sasuke is willing to overcome his own insecurities and ideals to return that respect to Naruto that he heard Naruto say at the final valley and land of iron.
Yes we can simply say feelings are earned, they are not earned all at once though, they are earned at the time that feelings have been developed long enough to some mutual end to have enough of a result that brings a positive outcome in those involved with the interactions and events that progress the building and outlook of people on each other that develops their feelings for others. Kinda like team 10, dysfunctional at first, but many events and trails later, they slowly became closer and more mature with each other over several events. Shikamaru stopped thinking of Ino as annoying and loud and choji (though his best friend) he did have a couple of "traits" he found to be a drag. Ino didn't like Shikamaru's attitude and though a big guy like Choji would drive Sasuke away, yet she eventually came to respect Shikamaru's intellect and found Choji to be kind. Choji was all just food and lacked some self esteem (not to the extent of HInata), even scared of his full power to a degree, yet he became more confident in himself and became better with not only Shikamaru and Ino, but everyone else, he was just simply himself, he didn't need to be anything anyone called him. Team 10, they did earn each other's respect, but they had to build those mutual feelings of friendship before they fully came.
NS and the other pairings, love is not earned all at once, its developed and built. Naruto has strived for Sakura's love but he has succeeded in becoming the best of friends with her. Sakura has even returned a bit of the mutual happiness. Yet will Sakura return this friendship as love? Its possible. This is why NH and SS cannot just happen or be earned, it needs to be built, yet this is something they are both lacking in greatly compared to NS, espcially now with NH in limbo (aside from past development lagging) and 635 with Sakura untrusting of Sasuke.