Obviously Naruto himself is a main character as the memory seal is related to him. Sasuke could also be involved, as he has a deep connection with Naruto and might notice the changes in him due to the seal.
In some 'naruto memory seal fanfiction', the seal might be a tool for an enemy. They could manipulate Naruto's actions by selectively removing or altering his memories. This could create a complex web of mystery and conflict as Naruto tries to figure out what's going on and regain his true self.
Well, 'sakura memory seal fanfiction' could potentially center around characters who have the ability to seal memories within the context of a sakura - themed setting. For example, it could be a fantasy story where the beauty of sakura is intertwined with the mystery of memory sealing. It could also be a love story where a character uses the memory seal under the sakura trees to protect their loved one from a painful past.
Since it's a 'sakura memory seal fanfiction', it might have a main character who is on a quest to understand the mystery of the memory seal. There could also be an antagonist, perhaps someone who wants to use the memory seal for evil purposes. There could be a sidekick character as well, like a small spirit that lives among the sakura trees and helps the main character on their journey.
The Karma Seal can change Naruto's appearance. In some fanfictions, it might give him a more menacing look with strange markings spreading across his body.
Well, 'Memory Seal Light Novel' could potentially revolve around a fantasy world. Maybe in this world, there is a powerful magic related to memory sealing. The protagonist might be caught in a web of mystery, where they discover that their own or someone else's memories have been sealed, and they embark on an adventure to figure out why and by whom. They could meet different allies and foes along the way, all while trying to understand the secrets behind this memory - sealing magic.
It could lead to some really interesting plot twists. Naruto's new ability as a seal master might give him an edge in battles and change the dynamics of his relationships with other characters.
The curse seal often gives characters increased power. For example, they might become stronger physically, able to take on tougher opponents. In some fanfiction, it can also change their appearance, like making their eyes glow or their skin take on a different hue.
One idea could be a fanfiction where a new character discovers an ancient and powerful seal mark that was forgotten. This character then has to figure out how to use it without getting corrupted by its power. It could lead to an adventure where they team up with Naruto and his friends to keep the seal mark out of the wrong hands.