After learning of his family heritage and having dealt with the threat of Kaguya Ootsutsuki, Naruto decides to take some time to wander the old ruins of the old Uzumaki Mask Shrine in search of some information of his clan.
While wandering around the shrine, he looks at the masks, and one sticks out to him. He reaches out to to mask to pick it up. When his hand touches the mask he feels a pull at his chakra and the mask lights up. The room begins to shake, and a hidden door opens. Behind this door, Naruto discovers a staircase to a hidden room. He enters the room and the torches light up to reveal a scroll sitting a top an alter. Naruto goes over to scroll and attempts to open it. The scroll begins to react to his Uzumaki chakra, similar to the mask that lead to the room, and opened. He looks inside.
Written in the scroll was a story of how the Uzumaki were a proud and powerful clan. It stated how they had an affinity towards different sealing and other secret techniques, as well has large amounts of chakra and longevity. As Naruto continued to read, it mention how how other clans and villages became jealous of the the Uzumaki and launched an attack on them and the village of Uzushiogakure. This caused many of the clan to go into hiding in fear of being killed due to their lineage. Unfortunately for the Uzumaki, they had a distinct feature with their unique red hair that was often a dead give away. Many tried the Transformation Jutsu, but it was merely an illusion technique that caused concentration and chakra to maintain.
When all seemed lost, a new jutsu was developed. It was a transformation jutsu of sorts that allowed for a complete physical transformation of the user. It used the some of the sealing techniques of the Uzumaki clan to create special masks. These masks would allow the user to transform into physically a different person, using whatever DNA or Chakra the user used as a base to create the mask.
It was amazing, after the user put on the mask, their chakra would be drawn to the mask and it would begin to fuse to the wearers face. The mask would then start converting the wearer's chakra to become that of the mask's base. From there it would begin physically changing its wearers body to an exact cellular double of the mask's base. It even copied the chakra (Think of White Zetsu's Substitute Technique). It seemed like a perfect solution, only it came with some problems.
It seemed once the wearer first puts on the mask, they begin to take on the personality of the mask's base. It is gradual at first, but after a while the user becomes lost in the personality of the mask. They mentally started to become what they wore. It also seemed that the stronger and more influential of the personality of the mask's base, the faster the the change would happen. Unfortunately, many Uzumaki became lost in their new identities and began to forget who they were to prior to the mask.
A way to remove the mask was then developed to stave off the change in personality. The Uzumaki found they were able to create a seal tag, that once applied to the forehead of a mask wearer, would reverse the bodies transformation so that way they could remove the masks. For now it seemed like a solution, until a new problem presented itself. There was a time limit to the masks. After three full days the fusion of mask and the wearer would be virtually permanent. It would take the chakra of the strongest of the Uzumaki clan being infused within a seal tag, that could ever remove a mask past the three day mark.
The Uzumaki found the risk of the masks, out weighted that of the reward. They sealed the knowledge of the jutsu needed to create the masks in the scroll.
Naruto finished reading the scroll and was amazed at what he found. Not only did he learn some of his clan's history, he also learned of a new clan jutsu as well. Realizing the risk of leaving such a risky jutsu around, he decides to roll the scroll back up and bring it back to the village. He knew it could be potentially dangerous if it made it into the wrong hands.
Naruto exits with the shrine and begins to make his way back to village. As he makes his way back he starts to begin thinking of the mask jutsu. He knew of the risks, but thought it couldn't hurt to try and make one mask right? Before he realizes it, he's back in the gate of the village. From there, he heads straight to...