A plot twist could be that Sakura and Hinata actually team up against Naruto in some way. Perhaps they realize that Naruto is being pushed into a relationship by the village elders for political reasons. So, they decide to fake a relationship between themselves to make Naruto see that he should be free to choose his own path and not be pressured into a marriage. This would turn the typical love triangle on its head.
One possible plot twist could be that the person Sakura is marrying is actually under a spell. For example, an enemy might have cast a love spell on him to get close to Sakura for some devious plan. Another could be that Sakura discovers at the last minute that the man she's about to marry has a hidden identity. Maybe he's a long - lost relative of an enemy she thought she had defeated. It would add a lot of drama to the story.
A plot twist could be related to Yugito's tailed beast. Maybe the power of the two - Naruto's Nine - Tails and Yugito's Two - Tails - has some unforeseen consequences when they get married. It could attract the wrong kind of attention from those who seek to use tailed - beast power for evil. Or perhaps the tailed beasts themselves have some sort of reaction to their union that changes the relationship between Naruto and Yugito, like they start to communicate with each other in a new and strange way through the beasts.
Well, perhaps a plot twist could be that an old enemy resurfaces but this time they target Hinata to get to Naruto. This forces Naruto to not only protect his new wife but also figure out why this enemy is after her specifically. It could also add a layer of drama if Hinata decides to take matters into her own hands and train secretly to be able to defend herself and Naruto better. Or, there could be a political plot twist where their marriage causes unrest in the ninja world because of Hinata's family status and Naruto's position as a hero, leading to them having to fight against those who oppose their union.
One possible plot twist could be that during their training, they accidentally discover a new and powerful jutsu. Maybe it's a jutsu that combines their unique abilities. Naruto's chakra control could be enhanced by Hinata's gentle fist style in an unexpected way, leading to a whole new form of attack or defense.
A plot twist could be that Naruto suddenly loses his ninja powers right before the wedding. This would create a huge dilemma as he is seen as a hero in Konoha. Sakura would then have to decide if she still wants to marry him without his powers. Also, perhaps a new character shows up claiming to be Naruto's long - lost brother and tries to stop the wedding because he has some grudge against their family.
One plot twist could be that Naruto discovers a long - lost family secret just before the wedding that makes him question his identity and whether he's truly ready for marriage. For example, he might find out he has some sort of special power inheritance that comes with great responsibilities.
Another plot twist could be that an enemy uses their relationship against them. The enemy could spread rumors or false information to create chaos and turn the ninja world against them. Naruto and Sasuke would then have to fight not only to protect their relationship but also to clear their names and prove that their love doesn't mean harm to the ninja world.
Another idea is that Naruto's death while protecting Sakura causes a rift between Sakura and Sasuke. Sasuke might blame Sakura for Naruto's death in some way, either directly or because he feels Naruto wouldn't have been in that situation if it wasn't for Sakura. This could lead to a complex and angsty storyline where Sakura has to deal with the guilt of Naruto's death as well as Sasuke's coldness towards her.
One possible plot could be that Naruto, after much soul - searching, realizes his deep feelings for both Ino and Hinata. In this fanfiction, the village might initially be shocked but then gradually come to accept their unique relationship. Maybe they all go on missions together and their bond deepens over time. They could face challenges like other villages not understanding their relationship and try to undermine it. But Naruto, Ino and Hinata, with their strong wills, prove that their love can overcome any obstacle.
Well, perhaps the person she marries is from a different dimension. This would bring in elements of exploring new cultures and powers. The marriage could be a political move to unite two very different groups. And Bulma, being Bulma, would have to navigate through all the new and strange things that come with this situation. It could also lead to her having to choose between her old life and this new one she's been thrust into.