The Shindo Life story involves a world filled with ninjas and various elemental powers. Players embark on a journey to become powerful ninjas, facing challenges like battles against other players or powerful in - game bosses. They can train, upgrade their skills and unlock new abilities as they progress through the story.
In Shindo Life story, the main character is of course the player's avatar, a ninja. But there are also important NPCs. For example, the village elders play a crucial role. They are the ones who often give out important quests and advice. And then there are the rival ninjas from other clans. They can be considered main characters in a sense as they drive the story forward through their actions and interactions with the player's ninja.
To get story mode in Shindo Life, check the game's main menu or quest log. Sometimes, you need to unlock it by achieving certain in-game milestones or interacting with specific NPCs.
Maybe Sasuke. Sasuke is extremely proficient in kenjutsu. In fanfiction, he could see Naruto's potential and decide to train him, sharing his knowledge of sword fighting with Naruto. This could also be a way for them to bond and grow stronger together.
One possibility could be Kakashi. Since Kakashi is already a very versatile ninja with skills in many areas including some swordsmanship, he could teach Naruto kenjutsu. He has the patience and the knowledge to pass on the skills.
You can start by looking on fanfiction.net. It has a large collection of 'naruto kenjutsu fanfic'. Just search for 'naruto kenjutsu' in the search bar, and you'll get a bunch of results.