He traveled through Naruto and became Naruto's twin brother. As soon as he was born, he saw the Fourth Hokage seal the Yin Nine-Tails in himself.

The Yin and Yang powers of the Nine-Tails had to be separated, so he was immediately entrusted by the Third Hokage to Jiraiya to be sent to Myoboku Mountain.

At this time, he awakened the system of becoming stronger by arguing with others.

In Myoboku Mountain, he was speechless facing several toads.

Arguing with toads... was useless.

So, he could only practice with the help of the Toad Sage, control the Nine-Tails, and learn immortal methods. It

was not until Orochimaru attacked Konoha and the Third Hokage died in battle that he left a will to tell Naruto.

In fact, you have another brother, exactly the same as him.

Naruto:? ? ?

Main characters: Uzumaki Kirito