One idea could be Naruto being transported into the Heaven's Feel world and having to deal with the Grail War using his ninja skills. Another could be a crossover where the characters from Naruto interact with the Heaven's Feel characters in unexpected ways, like Naruto befriending Shirou and teaching him some ninja techniques.
Another idea is Sasuke and Sakura in the '7 minutes in heaven'. Sasuke, who is often aloof, could be forced to confront his feelings for Sakura in that small, confined space. Maybe they start arguing at first, but then as the minutes tick by, they recall all the times they've been through together and it softens their relationship a bit. For example, Sakura could mention how she's always worried about him during his travels, and Sasuke might show a glimmer of his true feelings for her.
One interesting plot could be about a new character in the Naruto universe who has the power to control both heaven and earth elements. They could use this power to try and bring peace between warring clans.
One interesting crossover could be the characters from Naruto experiencing the intense magical battles in the Fate Stay Night Heaven's Feel world. For example, Naruto's ability to quickly adapt and his never - give - up attitude might make him an interesting participant in the Holy Grail War. He could use his shadow clones to scout the area or even fight multiple opponents at once, much like some of the Servants in Fate Stay Night. Another aspect could be the sharing of powers or techniques. Maybe a character from Fate Stay Night could learn chakra control from Naruto characters. It would be fascinating to see how the different power systems interact.
One idea could be a crossover where the Naruto characters end up in the world of Heaven Lost Property. Naruto's skills in combat and his determination could create some really cool scenarios when faced with the angels and devils in that world.
A plot idea could be that Naruto discovers a new, ancient form of chakra that has been lost for centuries. He then has to train to master this chakra while also dealing with the political implications within the Hidden Leaf Village. Some elders might be against him exploring this new power for fear of the unknown, but Naruto, being Naruto, is determined to master it for the good of the village.
One idea could be that the events of 9/11 somehow influence the Hidden Leaf Village. For example, they might tighten security and Naruto could be part of a new team in charge of protecting the village from potential outside threats inspired by the real - world event. Another plot could involve characters from Naruto trying to understand the concept of such a large - scale tragedy and how they can prevent similar things in their own world.
Another plot could involve a crossover with a post - apocalyptic world. The angeloids find themselves in a world destroyed by some great catastrophe. They have to use their powers to help the survivors rebuild and also face new threats that have emerged in this desolate world. For example, mutated creatures that are attracted to the angeloids' energy.
One plot idea could be exploring her relationship with Minato before Naruto was born. Maybe she had some premonitions about the future and tried to prepare Minato in some way. Another idea is that she could have had a secret jutsu or power that she passed on to Naruto without anyone knowing. And a third idea could be her having a role in the shinobi world that was cut short by her untimely death.
One interesting plot idea could be a time - travel story. For example, Naruto is sent back in time to the era of the First Hokage. He could use his knowledge of future jutsu and events to change things for the better in the past. Another idea is a story where Naruto discovers a hidden clan within Konoha that has a unique and powerful Kekkei Genkai. He then has to help this clan gain acceptance in the village. A third idea might be a story where Naruto is turned into a different creature, like a cat or a fox, and has to find a way to turn back while still dealing with the normal threats to the village.
One idea could be that Neji discovers a new hidden power within Naruto that he helps Naruto master. This could lead to them having to face a new, powerful enemy together.