I've always wanted to know what would have happened if they had found Obito instead of thinking he was dead the entire time. So here's what I think what would've happened. The story line starts when Rin was captured and the three tails was sealed inside her. I'm sorry if some facts are wrong.
"We need to get her back to the village!" The team of Jonin Kakashi was with were rushing towards the village carrying and unconscious Rin.
"The Kiri-nin are gaining on us, we won't make it on time. Our only chance is to stay and fight. Kakashi you take Rin back to the village, we'll hold them off as long as we can." Kakashi nodded and did as he was told. Jumping tree to tree as fast as he could. He could hear the battle cries and metal clashing. The Kiri-nin were closer then they had thought, soon enough they'll catch up to him. Rin looked bad, her face covered in bruises. Just as Kakashi went to jump to the ground, she started to stir in his arms.
"Rin. Hold on Rin. We'll be home soon." Instead of welcoming the thought of home, Rin looked horrified.
"What's wrong? Are you in any pain?" Rin started struggling in his grip. Clawing at his arms to loosen.
"We can't go to the village! It is dangerous! They'll break the seal as soon we get inside!"
"We're fighting them off. We need to get you to the village." Just as soon as Kakashi thought she was going to calm down, Rin jumped out of his arms. She ran the opposite direction, straight into Kiri-nin who had caught up to them. There were only three of them, easy enough to take down.
"We want the girl back." Two of the ninja came at Kakashi as the third went for Rin. They lunged at him kunai in hand. Kakashi easily evaded the attacks and knocked the both out trying to save the energy he didn't have. He looked around, Rin was nowhere in sight. Her chakra was faint but he detected it none the less. She was close to the village. Even though they claimed to want her, they fought defensively and pushed towards the village. So what Rin said was true, they wanted her inside the village. Kakashi found her facing her opponent. She had no weapons to defend herself, so Kakashi stepped in.
"Kakashi it doesn't matter what you do to them, I can't go to the village. You have to kill me! I can't do it myself. It's the only way Kakashi."
"I told Obito I would protect you. I made a promise to him and I vow to keep it." Kakashi fired up his Chidori and rammed it straight into his target's chest. Only his target wasn't the enemy. Rin had jumped in front of him plunging his Chidori right into her heart. Kakashi was shocked as Rin's blood spat out of her mouth and onto his face.
Kakashi fell to the ground out of strength and chakra. The death of his friend taking a great toll on him. He was still conscious and was able to tell more Kiri-nin had shown up. He couldn't fight them off he could only hope his village would send backup. He looked and seen Rin lying dead on the ground no more than two feet away from him.
"Aaarrrghh!"
-Someone's screaming. I can't tell where it is coming from. Everything's spinning. I can't stay awake much longer. I..I can't...-
"Who are you boy? Doesn't matter kill him! Leave the girl she's useless to us now." Kakashi could see a team of Kiri-nin surrounding someone.
-He's the one who was screaming? But why? I've never seen him before. He must be an enemy. Then why are the Kiri-nin attacking him? If I could just get good look at his face maybe I could-
The boy who screamed lashed out in an uncontrollable rage. He killed the group of ninja, without mercy. The weird things came out of his back looked like plant vines or stems just bigger. It was all over far too soon. No life was spared in his fit of fury. The boy started to walk over to where Kakashi was.
-He must've realized I'm still alive. I don't have the strength to fight. Maybe I could run. Where's the honor in that? To die for my village is a great honor. Rin it looks like I'll be seeing you soon. Wait for me o...-
The boy knelt to the ground, lifting Rin's body into and intimate embrace. When he put his face to hers his hood fell and Kakashi could see clearly who the boy was.
"O-Obito?" With his last breath, Kakashi whispered Obito's name, loud enough for him to lift his head to see Kakashi fall unconscious.
*Time lapse*
Kakashi opened his eyes to see a darkly colored ceiling. His head hurt and his body ached but that wasn't the worse of his problems, he didn't know where he was. It was obvious he wasn't in the village. He could sense there was someone else in the room with him, though he hadn't noticed Kakashi waking up.
-Obito. That's right I saw him hold Rin. Maybe it wasn't him. Maybe it was his mind playing tricks on him due to exhaustion. No. It was him. He chakra signature was too familiar to be a coincidence. How could he be alive? How could he be alive and not come back to us? He probably felt deserted.-
"Obito. I'm sorry we left you. I'm sorry I broke your promise. There's no excuse, I made a vow I couldn't keep. How could I ever face you now? I don't deserve to face you." Kakashi closed his eyes. He hadn't realized he said those words out loud, causing the other person in the room to walk over to him.
"It appears you have regained consciousness. How do you feel? You took a great deal of pain. The cells I placed in your body seem to be taking effect. You should be able to move freely in a few days. Why don't you tell me your name and your relationship to my apprentice, Obito." Kakashi opened his eyes and saw an old man with long white spiky hair.
"I am not obliged to give you my name or any other information that does not concern you." Kakashi tried to get up but failed when a tremendous amount of pain shot through his body.
"Like I said you won't be able to move for a couple of days and that is because of the time I put into healing your body. So as a payment for my kindness, you will answer my questions. I understand your concern for your village, but let me assure you I have no interest in any information you have regarding of that village or any other for that matter." Kakashi took what he said but his answer did not waver.
"I never asked for your help. My comrades would've come and taken care of me just the same as you have. I owe you nothing, you did this on your own occur." -This man helps me and only wants to know how I know Obito. How did he know about us in the first place? It must have been Obito who brought me here. This man wants to know why his apprentice would bring a stranger to him, ask him to heal me and didn't tell him anything about me. If it me in his position I'd want to know too.-
"My name is Kakashi. I am an old comrade of Obito's." -There that should satisfy the old man.
"Oh. So you're the friend he's been keeping tabs on. You and that girl he brought I presume."
"He brought her here? No that's not possible! She died saving her village. She should be honored and buried as a hero!" The man only looked at him with a blank face. Kakashi was in even more pain, his shock caused him to sit up in a fast and painful matter.
"It seems your healing has progressed a lot more than I thought. Although, it does hurt to sit like that doesn't it?" Kakashi took a look at himself. He was halfway off the bed he laid on, with his knee pressed to his chest. So painfully he straightened himself all the way up to test his ability to walk. It was painful but he could manage, for now.
"Where is Obito? And why'd he bring us both here, in this..place? And furthermore, who exactly are you?" He gave the man a stern look, the best he could muster up. He needed answers just as much as he needed to get back to the village. His comrades will think he was dead if he wasn't back soon.
"So many questions. I suppose I could tell you who I am but, is there any reason for you to believe me? I could tell you a name never heard of or a name of an innocent man. How would you ever know if any of it were true? Also, this place isn't on any map. No one knows of it and it can not be found. Not even Obito knew the whereabouts of his own being, that is until he busted the wall right open two days ago."
"Two days? I've been out for two days? His did Obito even manage to carry the both of us here? Why did he bring us here?" Just then a door swung opened and these strange looking men walked through, along with Obito.
"Kakashi. That's enough. I'll answer all of your questions once you've answered mine." The two boys stared each other down, both felt the intensity of their awkward encounter.
"Why did you kill Rin?"
