Another idea is that the tattoos are a curse. An enemy of Konoha placed a dark curse on Naruto that manifests as tattoos. These tattoos slowly drain his chakra and he has to find a way to break the curse while still being able to protect the village and his friends.
Well, he might get a tattoo of the Rasengan on his palm. Since the Rasengan is one of his signature moves, it would be a cool and meaningful tattoo. He could also have a tattoo of his master, Jiraiya's, book mark. It would be a way to honor his mentor. Additionally, a tattoo of the chakra pathways on his body could be an interesting concept, highlighting his ninja powers.
One idea could be a story where a young ninja discovers an ancient ANBU tattoo on their body that holds a hidden power. They then embark on a journey to find out the origin of the tattoo and how to control its power. Maybe it's linked to a long - lost ANBU clan.
The tattoos could also make him more of an outcast in Konoha initially. Some people might be afraid or judgmental of his new appearance. This could make Naruto feel a bit isolated, but it could also strengthen his bond with his closest friends who accept him regardless. He could then become more determined to prove that he's still the same Naruto, tattoos or not.
Maybe the runic tattoos are a sign of a hidden heritage for Harry. They could be linked to a long - lost family line that had some unique connection to runes and their magic. This would add a whole new layer to his character and his place in the wizarding world.
There could be a fanfiction where Naruto gets tattoos as a form of rebellion. Tired of being the 'good boy' of the village, he decides to get tattoos that are frowned upon by the elders. These tattoos might have a deeper meaning related to his past, like markings that represent his parents in some way. This causes a stir in the village, but Naruto stands by his decision, which also helps him grow into a more independent and self - assured person.
In fanfiction, some popular Naruto tattoos include the Uzumaki clan symbol. It represents Naruto's heritage and is often depicted on characters as a sign of their connection to Naruto or the clan. Another one could be the Sharingan tattoo, which is related to the Uchiha clan and is often used to show a character's power or their relation to Sasuke.
One idea could be that Naruto gets tattoos as a form of self - expression in prison. Maybe he uses the tattoos to tell his story or to mark his growth. For example, he could get a tattoo of the Hidden Leaf symbol but with a twist, like it's broken in some way to represent his broken relationship with his village while in prison.
One interesting idea could be the combination of Naruto's ninja skills with mecha technology. For example, Naruto might use his chakra to power up the mecha in unique ways. Another idea could be the new enemies that are created specifically for this mecha - Naruto concept, like robotic shinobi that require different combat strategies compared to normal foes. Also, the design of the mecha Naruto itself can be really cool, perhaps with features inspired by the Nine - Tails.
Another idea for a fanfiction is that the lyrium tattoos are part of a prophecy. Naruto, being the main character, is the chosen one to bear these tattoos. His friends might be initially skeptical or worried about the strange markings. But as the story progresses, they realize the tattoos are the key to saving the ninja world from a new, powerful threat.
Another idea is that Aizen somehow ends up in the Naruto universe during the time of the Fourth Great Ninja War. He could try to manipulate both sides for his own gain. But Naruto, with his ability to see the good in people, might try to reason with Aizen and show him a different path. It could be a story of redemption or a great battle if Aizen refuses.