Senju and Uchiha are trapped in an eternal battle between Clans with the Senju keeping the upper hand. Ever since the day Madara and Hashirama became enemies, the bond of friendship between them ceased to exist. Both their fathers had died in battle and what was left was each one's younger brother. When Madara's only brother, Izuna, supposedly died by the hand of Hashirama's younger brother, Tobirama, the hatred of Uchiha grew to its vast.
However, Tobirama knew that that wound was not fatal. That's why he was shocked when he heard about Izuna's death. When he looked at him though, he realized the real reason, why Izuna died…
It wasn't the wound, but the loss of his eyes. Madara used that wound as an excuse to make it look like Izuna gave up his own eyes because he would be dying.
"You… What did you really do to Izuna? It wasn't that scar! Tell me!" he yelled anraged at the older Uchiha.
"Tobirama! Calm down..", Hashirama tried to hold back his younger brother.
"I told you. My brother died by your hand and he left me these eyes so I could protect our Clan and its future."
"You're lying! I know myself that he—"
Tobirama stopped as he realized that if he would speak more, he would reveal his and Izuna's secret and that's something he couldn't allow to happen.

Izuna and Tobirama swore to never tell anyone about their relationship and to do that, they had to pretend they were fighting a real battle whenever they clashed. When the two Clans were having a break from engaging one another, Tobirama and Izuna would be the ones usually patrolling. The first time, they were surprisingly calm and talking normally with each other. Like the War between the two Clans didn't exist for those few hours of patrol.
"Oi!"
"Yo!"
"You're not going to pass on any further."
"I wasn't planning to do so, Uchiha."
"Then you should head back before I attack you again."
"I wouldn't do that if I were you. If you attack me now, both our Clans will rush to help us and the fight will go on again. Both sides are tired enough, so this would cause a huge ruckus."
"Hn..you're probably right, Senju."
Just like when Madara and Hashirama met for the first time, Tobirama and Izuna were facing each other with a river in between them. They were just sitting there, looking at each other, being extra cautious. They were both 16 by that time. Both of them were full fledged shinobi and of their Clans' strongest men. This first night of patrolling was the first time they had a conversation. After their shifts ended, they didn't even turn around to see each other take his leave. They just left.

Another battle between the Clans was about to begin and Izuna andTobirama were once again ordered to patrol the area. The same spot, the same ignorant expressions on their faces. This time, Tobirama didn't seem to have been all that tired from the previous battle. He thought of attacking Izuna while he was trying to save up his chakra for their next clash, but that would go against his morals.
"Oi, Uchiha! You're Madara's little bro, right?"
"Yes.."
"Tell him he's an asshole!", he said with a slight smirk on his lips.
"How dare you insult my brother like that!"
Izuna took out his kunai knife and pointed at Tobirama. He was aiming for his head and ready to throw it.
"Calm down. I don't want to fight someone who's unable to defend himself. Your chakra is weak, I can sense it. We can spare on the battlefield, like we usually do, if you wish."
"Hmph..". Izuna put back his kunai.
This time, their shifts seemed awfully long. Only an hour had passed, but it felt like it's been half a day. The air was hot due to the season and days lasted longer than nights. It was tough to last longer than three hours on a battlefield while being constantly attacked, even for a skilled shinobi.
"Hmph.. Hey.. You charged up yet?", Tobirama suddenly spoke up and asked the Uchiha.
"Why?"
He had a puzzled look on his face...
"I'm bored. Let's fight!"
"If you wanted to fight you should have said so earlier. I don't need your pity, you know."
"I'm not pitying you. You're an Uchiha. You're strong. Although, I'm stronger.". Again that smirk.
"Tsk.."
Izuna got ready to face his opponent with all the energy he had. He didn't intend to call for any reinforcements. Tobirama had been his rival ever since they saw each other's faces for the first time. Izuna was strong as an Uchiha, indeed, but he was also very soft. Whenever he attacked, he would avoid vital spots and just knock his opponent out. Hashirama knew that as well and that's why he told Tobirama to go easy on on his rival. As years passed, Tobirama got used to fighting Izuna over and over. He kind of started liking the guy, since they were often missing on purpose, just to see each other's reaction. But after both of them became teenagers, he looked at Izuna differently. He thought the boy was fragile and not flexible at all. He moved like a girl sometimes and Tobirama used to make fun of him.
"Alright..come at me!". He was ready to face Tobirama. His chakra wasn't fully recovered, though. That made him worry a bit.
"Hm.."
Izuna took position and was ready to make his move when suddenly, in the blink of an eye, he felt his entire body being pushed back and paralyzed. He started feeling dizzy and couldn't see clearly anymore. He had used his Sharingan too much during the previous battle and exhausted his eyes a lot. He couldn't feel his hands anymore. It was like someone had tied them very tight with a rope and his eyes were covered with some kind of cloth. It all happened so quickly… With the back of his head touching the ground and both of his hands immobilized and stuck behind his back, he felt some sort of pressure from above, like someone was sitting on top of him.
"Hng…ha…what..is this..?!"
"I slowed you down by exploiting your weak chakra and pinned you down like a fly."
A male voice whispered gently into his right ear and he could feel a hand touching his forehead and brushing back his soft hair a little.
"If you call for help I'll cut your throat right away. Do you want to die without even having spared with me in a real battle? You're weakened now, Izuna."
"Ghh.. get..off of me..", he struggled.
"Sorry, but no can do. Now that I've finally pinned you down, let's talk!"
"You want to.. talk..?"
Tobirama stroke his hand over the Uchiha's pitch-black hair and took a deep breath.
"Do you.. feel happy, Izuna?"
"What kind of question.. is that?Hgg.."
"A simple one, really. What do you think about our brothers fighting over and over again? If it was me, I would have annihilated the Uchiha long ago. Iwouldn't be as kind as my brother is.. or as you yourself are.."
"I'm.. not kind.."
Izuna struggled to get loosen his hands, but Tobirama was holding the ropes very tight with his left hand. Izuna's teeth clenched as he tried to free himself.
"Ya know, out of the whole Uchiha trash bin, you're the only one I kind of.. like.."
"Hggh..what..?"
Tobirama held the young Uchiha's hair tighter and pushed his head backwards and hit it on the ground.
"Damn you.. Izuna.."
He wrapped the rope around his arm and slowly stroke Izuna's right shoulder with his hand. Then he leaned forward and with his face only inches away from the Uchiha's, he looked at his facial characteristics. He resembled Madara very much, but then again, they were so very different. Madara was ruthless, while his brother was the opposite. Izuna may was willing to help the Clan and support it by all means, but he never performed ruthless attacks against whoever he was fighting. Tobirama was much like Madara in that case. All he had in mind was victory, much unlike his older brother, Hashirama, who yearned for peace.
He felt Izuna's warmth through his body. How fast his heart was pounding. The boy was strong as a fighter, but easily deceived by heart. Tobirama closed his eyes and leaned more forward. The closer he got, the faster his own heart pounded as well. What he hoped for now, was that no one would see what was about to happen.

It felt so relieving. Soft and gentle. Warm and welcoming. Izuna's lips tasted like red fruit tea. Naturally, they would avoid drinking tea in such a situation since it gets someone sleepy, but tea was also helpful in healing wounds faster and alleviate the body. It may have just lasted for an instant, but to Tobirama it felt like they were like this for a long time. Izuna's body felt a sudden relief, too. He didn't try to push away the young Senju,- not that he could, tied up like that - but still, he showed no resistance. Tobirama lifted his face again and stared at the boy. Without having realized it, he accidentaly had let go of the rope and Izuna could now move again, but then…Tobirama was the one paralyzed. He couldn't believe that he gave in that easily. A desire like that for an Uchiha's body and moreover… a man's body. He felt ashamed of himself. His eyes were half closed and he still couldn't move a bit. Then he felt a light touch on his shoulder. It was a hand. Izuna's hand. He went his fingers softly over Tobirama's neck and reached his cheek. The Senju's body was cold. He stroke his neck again and reached for the back of his head. He felt the his snow-white hair sliding through his slim fingers. He took off the piece of cloth with his other hand and looked at him.
"Are you-..?"
Izuna saw the boy, who overwhelmed him moments ago, shedding tears right before his very eyes. It was the first time he saw Tobirama's cheeks being painted by tears like that. Izuna smiled and whipped away the tears on one side of the boy's face. Tobirama was able to move again and covered his eyes with both of his hands with Izunas hand still touching his cheek. TheUchiha lifted up his upper body and took both of Tobirama's hands off of the crying boy's face. Looking down, he had become red out of embarrassment. He placed Tobirama's arms down and gently wrapped his hands around the Senju to embrace him.
"You were right.. Looks like I really am very kind..". The Uchiha was the one smiling this time.
He let Tobirama cry on his shoulder and gently patted his back. He felt the deep breaths he was taking and how much out of tact they were because he was so excited. They stayed like this for a while until he had calmed down. Izuna's shoulder felt stiff because Tobirama was taller than him, so he had to stand upright to support him the whole time. When they broke the embrace, Izuna didn't look him in the eyes, but with both of his hands, he touched his ,- now dry from all the tears-, cheeks. His body was now warm. Tobirama slowly raised his left arm and held on on Izuna's hand.
"Why didn't you… use your sharingan?" the Senju asked.
"Hm.. I couldn't.."
"Hm?!"
"You see, not only you, but I am also not comfortable with fighting someone who's unable to defend himself."
"Tsk..". Tobirama seemed annoyed, but also smiled.

The day was almost over and a new battle was to begin. The two young boys both left the river without looking at each other going away, once again.