The Uchiha - Senju Immortal

[Author Note: Hello, my dear readers! For the ones that are seeing this chapter at the same instant it was released, get to know that this will be the new schedule, well, that's it, cya!]

I felt amused, seeing their questioning gazes, that they sent to each other so I only stared as Madara said with an expression that said 'You're suspicious' ''How can he be you nii-san if he's my nii-san?! Do you wanna fight?''

Hashirama felt offended and said with a bit of anger, provocatively ''Even if we fought, I would win, he isn't your nii-san, he's my nii-san, Senju Shiro!''

Hearing this, Madara stopped to think and said ''Is that so? I won thirty times while you also won thirty times, we're on a tie, stupid! Besides, my nii-san is also called Shiro, Uchiha Shiro!''

The silly Hashirama felt that everything his best friend and rival said was right, I was almost laughing my a.s.s off seeing this as both of them looked at me, waiting for an answer ''Well, well, both of you are really similar, hahaha! You two probably don't know but... I'm both Uchiha and Senju Shiro because my father is Senju Asuha while my mother is Uchiha Yiyi!''

They fell to the ground, utterly shocked, realizing each other true identity, they said at the same time ''Wait... you're from the Uchiha/Senju clan?!''

As I thought, they didn't know their best friend or rival true identity before I arrived here, I think these two brats will be my daily novel, they're really fun, I thought that one of them was already fun but the two together is simply a stand-up!

''So my nii-san is also from that hateful clan...'' Madara muttered and earned a smack on his head ''Are you saying I'm also hateful, Ma-da-ra?'' I said, heck, your only friend is from the Senju Clan, can you at least don't say it is that?

''O-oh, I was just joking, Shiro-nii-san, now that I look again, the Senju Clan seems so lively and... lovely?'' Madara said, trying to find good words and said the last one with a doubtful face, not sure if it was truly what he wanted to talk.

Meanwhile, Hashirama just had a thoughtful face before he just shook his head and said with a silly smile ''Haha, now I understand why you always leave for two years, tch, nii-san, to think you managed to fool me for such long time!''

I facepalmed... ''Don't tell me you truly believed I was playing hide'n'seek all these years?''

Hashirama immediately shook his head continuously as he said nervously ''O-Of course not, I knew from the start you left the clan for two years, I wasn't searching at all!''

''Puhahahaha!'' Madara laughed loudly, seeing how dumb Hashirama acted but quickly ran as he saw the angered Hashirama running towards him with a sword ''Tch, run because if I catch you, I'll cut you in a thousand pieces!'' the brown-haired boy said, dissatisfied that his rival managed to run.

I just observed them silently, wondering how good it would be if I had a friend like that, my only friend ever was Mito, not counting my own family, well, I don't know if the Hyuuga Tokuma counts, the one that fought alongside with me, not sure if he's still alive, who knows.

I also wonder if he would be kind enough to give me a bit of his blood for research, I saved him, after all, hn.

The two little brats were fighting each other as I thought how much of a waste I did, though the experience with the 'Perfect Body' failed, I felt it wasn't so simple, everything in my calculations at this time was correct, anyway, the important thing is that with chakra, my research over genes would advance tremendously because with it, inspecting and analyzing the genes would be much, I mean, much easier.

Differently from ordinary persons, my chakra is absorbed from the surrounding area, that produces Natural Chakra, on the start, I needed to absorb from external sources but after my chakra reserves increased, I, myself, started to produce Natural Chakra from my body naturally, which is one of the reasons I didn't die of exhausting completely my chakra and even overusing it.

Besides, with Natural Chakra, I can inspect my body and genes closely and understand how it works, with my knowledge from a modern, advanced world and also my own knowledge, after all these years, of course, I didn't only trained, I obtained blood samples from ordinary ninjas without Kekkei Genkai and from Senju/Uchiha Clan.

If you inject the cells of a different clan inside the body of another person, the cells will immediately try to reject it but if the injected cell is ''stronger'', it will try to consume the old cells, however, if the opposing cell has the same ''strength'', they will fight each other to death and the person will die.

However, if they have the same strength and there's something trying to fuse them like... Natural Chakra, it will succeed, for example, the reason Madara managed to survive the fusion with Hashirama cells in the future is: The fact that he's the reincarnation of Indra help with the fusion and that his own cell ''strength'' was similar to Hashirama cells and due to Hashirama cells having a hint of Natural Chakra, he succeeded. [A/N: Take a note that this isn't shown in the anime or manga but something that I made, don't try to kill me for that, 'kay?]

As long as I understand how the cells I want to fuse in my body or a different person, I just need to fuse it with the right steps and use my Natural Chakra as a mediator, well, no use thinking about that before I get a blood sample of someone from a different clan.

My thoughts were interrupted as Hashirama and Madara came near me and both of them said at the same time ''So... Shiro-nii-san, who won?!''

They looked expectantly at me, scratching my head in embarrassment, I replied ''Well... I was lost in thoughts so I couldn't see who won, haha... however, judging from your injuries, let's just think of this as a tie!''

Hashirama and Madara looked at each other and nodded, laughing, I said ''Haha, it's getting dark, little Hashirama, you should go home before it gets too dark, as for you, little Madara, you'll go to the Uchiha Village with me!''

Laughing in a silly manner, Hashirama nodded before saying ''Ok! Bye, Shiro-nii-san, come here to fight with us, I feel that fighting with you, I and Madara will improve faster, also, you can teach us cool jutsus, right?!''

''Yeah...'' I replied before I went back to the Uchiha Village with Madara, today was a good day, I guess.