A new year

Morning, Konoha, Year 43

The morning sunrise marked the start of a new day. In the house of Namikaze, Ren woke up with a new determination to achieve his goal. In the courtyard behind the house, he started doing some light exercises. Breathing the fresh morning air, his body was filled up with a refreshing feeling. It's been 10 years he had came into this Ninja World. He found a family he always dreamed of in his last life. He lost his family due to him being weak and his loving elder sister Aino died to protect him. The guilt, the burden, the anger he felt during that time is still fresh in his mind. Though he awakened the most powerful dojutsu in his clan, the price that he has to pay, didn't make him happy. Every time he think of his Rinne Sharingan, the smiling face and the parting words of Aino comes to his mind. The helplessness of his mother that forced her to do the very thing that she and father fought against is still unforgivable for him. If he would have been strong, he could have change the outcome. He wouldn't have to part with his mother. Now to save her he would have to turn a blind eye to the death that will follow in the upcoming war against Madara and his associates.

Shaking his head and clearing his mind from the thoughts, he started doing heavy exercises. We wants to follow the training of Rock Lee to strength his body. He also has an overwhelming advantage against Rock Lee, his body. Unlike normal humans, Otsutsuki clan members has a stronger and more powerful body. Though not everybody's body could compare to a Sage Body, he has a feeling his body is more powerful than a sage body. Being a pure blood Otsutsuki has it's own perks. Hagoromo and Hamura's body couldn't compare close to him.

"I guess, I will have to discover all the hidden abilities of my body first."

He started looking for a kunai and cut a small line on his palm. Within seconds, his body started regenerating. When a minute, there was no scar to be found.

"Regeneration check."

Then he continued with his heavy exercises.He did push ups till his body couldn't move. Immediately, he started doing meditation. Due to exhaustion, unwanted thoughts didn't come to his mind. In less time, he entered deep meditation. Though he has not reached the state of forgetting himself, he is not far from it.

While meditating, he could feel a cool feeling passing through various parts of his body. He guessed this must be his chakra repairing and strengthening his body automatically through the seal. He once again confirmed his guess and continued his exercise after his body recovered. Constant breaking down and repairing, made his body tougher. He thought if he didn't have powerful body, doing this kind of training would have harmed his body. He didn't know how Guy and Rock Lee trained their body to the point they could bear the strain of opening the Eight Inner Gates. Just the pain brought by from the opening of a gate, is unbearable for people with weak mind.

"I guess this explains their behavior. Their brains must have been numbed from the continuous pain. They really do deserve respect. With no ninjutsu talent, they reached a state beyond possible for humans. I will have to be friends with them and try if they teach me the Eight Inner Gate Formation. I have a feeling, I can open the Gate of Death and manage to live with my body' regeneration. Though I don't want to try it in any case."

He made up his mind to learn how to open the gates. If possible he want to create a new method from this to permanently open some gates to take advantage of his body. With his Byakugan powered up by Rinne Sharingan, it is possible to do it. As for how much time it would take, well lets just say Minato took 3 years to complete his rasengan. Though with his previous knowledge he could complete it quickly.

When he was lost in his thoughts, Minato came by and watched him training. Seeing him like this, a fire rose from his heart. He decided to put much more efforts in his training. Kushina also started working hard to control the power of nine tails. Within just two days, she could control power of two tails completely without loosing her mind. Ren advised her to mix her chakra with Kurama's and try to learn the Yin release and Yang release from him. Though complete mastery is not possible, if she could learn how to use Yang release for healing and Yin release for improving her spiritual energy, her body could use these chakra to self repair and strengthen her both physically and spiritually. Which will ultimately increase her chakra reserves much more as shinobi mix spiritual and physical energies to create chakra.

This is an idea he came up with in the cave that night. If she could properly improve her body and mind using Kurama's Yin and Yang chakra and learn something from him, it could prove his theory correct. She could become a human shaped tail beast without the help of Kurama if she managed to learn properly. In this way, he could use the same technique on Minato and help him improve his chakra reserves. This will also prove his another theory correct, chakra helps in changing the fundamental body structure. As Hagoromo distributed his chakra among people which, after generations, helped them in evolving their bodies to what it is now. This will make his future path easier.

Well all this needs time to test the results. He has no plan on becoming a mad scientist in the pursuit of power and immortality. Not that he can't become one. If her mother's teaching is true, then he at least has 1000 years of lifespan and he could improve it by mastering Yin-Yang. Well his brothers could master some initial usage of this using Rinnegan and Tenseigan. If he couldn't master them with his IQ and knowledge, then he should just give up his Rinne Sharingan to someone else and die a shameful death.

With all of them busy in their training, a year passed by.....