Perhaps Naruto makes a deal with the Shinigami. In the Naruto universe, deals often have consequences. He might offer something in return, like a part of his chakra or a future favor, in order to get the weapon.
It's possible that Naruto inherits the weapon. There could be some connection between Naruto and a previous owner who had a bond with the Shinigami. When the time is right, the weapon finds its way to Naruto, like it's fated to be in his hands.
Another way could be through inheritance. Maybe it was his father's or some distant relative's weapon. However, it was sealed away for safety reasons. As Naruto grows stronger and faces greater threats, the weapon reveals itself to him. It's as if the weapon senses that Naruto is the right person to wield it at that crucial moment.
It could be a sword. In many fanfictions, swords are common powerful weapons. Since the Shinigami is often associated with death and power, a sword with special abilities like being able to cut through spiritual barriers or absorb chakra could be a likely weapon for Naruto to obtain.
Well, in some fanfictions, the Shinigami might save Naruto by using its special powers to reverse a fatal curse or injury. For example, it could extract a harmful entity that was about to kill Naruto from his body.
Maybe the Shinigami uses its special powers to heal Naruto's severe injuries. For example, it could transfer some of its own spiritual energy to Naruto to revive his fading life force.
If the gift is a power - enhancing jutsu, Naruto could become much stronger physically and in terms of his ninja abilities. This would make him more confident in battles and able to take on tougher opponents.
The original Naruto story is mainly about Naruto's journey to become Hokage and the conflicts within the ninja world. However, the 'naruto contract of the shinigami fanfiction' takes a different turn. The contract with the Shinigami might introduce a darker or more mysterious aspect to the story. It could change the way characters interact, as they now have to deal with the implications of this new contract. The fanfiction may also have different rules regarding power acquisition and usage compared to the original, as the Shinigami contract could bring its own set of unique mechanics that are not present in the basic Naruto lore.
It might re - imagine it by adding elements of the Shinigami world. For example, there could be new types of jutsu related to Shinigami powers.
Perhaps he stumbles upon it during one of his adventures outside of the village. It could be in an ancient ruin or something.
He could start by training intensively with different weapons under the guidance of some old and experienced ninja. They might teach him the proper techniques and stances for using each weapon effectively.
In some fanfictions, Naruto might obtain the Kyuubi's bloodline through a special ritual. This could be a ceremony performed by a powerful shinobi or a sage who has the knowledge to transfer the essence of the Kyuubi's power into Naruto's genetic makeup, thus giving him the bloodline.