A possible plot is that a character from GTA, like Tommy Vercetti, finds a strange portal that leads to the Naruto universe. He enters and meets Naruto. Tommy is amazed by the chakra and ninja abilities. Naruto, on the other hand, is interested in Tommy's guns and modern ways. They decide to exchange knowledge. But then, a group of rogue ninjas and some GTA gangsters team up to stop them, thinking that their alliance will disrupt the balance of both worlds. Naruto and Tommy then have to fight against this combined force.
Perhaps the Orochimaru from Naruto is interested in the genetics and technology in GTA V. He tries to create new ninja - like beings using the resources and knowledge from the GTA V world. This causes chaos as his experiments start to run amok in both universes. The protagonists from both sides then have to work together to stop Orochimaru's mad plans.
An interesting plot idea for Naruto fanfic might be to focus on the life of a minor character. For instance, what if we told the story of a genin who never made it to be a chunin but still had a significant impact on the village in some other way? Or a story where all the ninja abilities are suddenly switched among the characters, and they have to adapt to these new powers while still facing their usual enemies. This could lead to some really fun and unexpected character interactions.
In a Naruto - GTA 5 fanfiction, it could be interesting if the ninjas had to adapt to the technology in GTA 5. For instance, Naruto might be confused by guns at first but then learn to use them in combination with his kunai. Also, the concept of the tailed beasts could be related to some powerful and dangerous substances or artifacts in the GTA 5 world. Maybe the Nine - Tailed Fox's power is locked inside a secret military base in GTA 5, and Naruto has to break in to regain his power.
One idea could be that Naruto discovers a hidden power within Shenron. For example, instead of just granting wishes in the traditional way, Shenron could offer Naruto a special training regime that enhances his already powerful jutsu. This could lead to Naruto facing new and even stronger enemies.
Another plot could be Samui getting involved in a time - travel adventure. Maybe she gets sent back in time to the era when the ninja world was just being formed. She then has to use her modern - day knowledge and skills to survive in that primitive yet dangerous time, and also has the chance to change the course of ninja history in small ways.
One idea could be that Tayuya, after being defeated, has a change of heart and teams up with Naruto to fight a new common enemy. They could learn from each other's skills and jutsu.
One idea could be Shinachiku going on a journey to discover his own unique ninja skills, different from his father Naruto. He could encounter new enemies and make unexpected allies along the way.
One idea could be that Ageha has a special power that only Naruto can help her control. This power might be related to some ancient ninja art. So, they go on a journey together to master it and along the way, they face many enemies and also make new friends.
One interesting plot idea could be a story where the Mizukage and Naruto have to team up to stop a new and powerful enemy that threatens both their villages. Maybe this enemy has a unique jutsu that can disrupt the balance of chakra in the world. Another idea is a fanfic where the Mizukage visits Konoha and Naruto is tasked with showing her around. During this time, they exchange stories about their respective ninja upbringings and learn from each other's experiences. A third plot could involve a time - travel scenario where Naruto goes back in time and meets a younger version of the Mizukage and they end up changing the future of their villages in unexpected ways.
One idea could be Naruto starting college as a total newbie but quickly making friends through his unique charm and determination, like he did in the original series. Another could be a story where Naruto has to deal with academic rivalries that are as intense as his battles in the ninja world. Maybe he has a rival in a particular class who constantly tries to outdo him in every assignment.