A plot twist could be that there is a prophecy that Naruto's marriage to Anko will either save or destroy the village. This puts a lot of pressure on their relationship. Some villagers might find out about the prophecy and try to break them up, while others might support them, believing they can save the village. This creates a whole new set of challenges for their secret marriage.
One possible plot twist could be that Anko is actually working undercover for an enemy organization all along. She got close to Naruto to gather information, but then truly fell in love with him during their relationship. Naruto would be devastated when he finds out and have to decide whether to trust her again or not.
It could be possible in fanfiction. Maybe Naruto discovers a different side of Anko that he's attracted to. They might get married secretly to avoid the chaos that would ensue in the village due to their unexpected union. But in the real Naruto storyline, their relationship is not at all hinted at in that way, so it's purely a fan - created idea.
A plot twist might be that Anko was once in love with someone else, and that person suddenly returns. Naruto would then have to compete not just with his own insecurities but also with this new rival. Or, it could be that Naruto's crush on Anko is part of a genjutsu placed on him by an unknown enemy. When he breaks free from the genjutsu, he has to re - evaluate his feelings for Anko, and Anko has to deal with the fact that Naruto's feelings were not entirely real at first.
In fanfiction, if Naruto secretly married Anko, it could lead to some interesting character developments. Naruto might become more protective of Anko, and Anko could soften Naruto's more impulsive side. Their relationship could also bring new alliances and rivalries within the village, as different characters react to their union. It could be a great opportunity for the fanfic writer to explore different aspects of the Naruto world and its characters.
Well, a plot twist could be that Hinata is actually from a future where something bad has happened, and she came back in time to marry Naruto secretly to change the future. Maybe in the original timeline, Naruto dies or the village is destroyed, and their secret marriage is a key to prevent that. Also, there could be a character who is jealous of their relationship and tries to expose their secret marriage, creating all kinds of chaos and drama.
A really interesting plot twist might be that Naruto discovers he has some sort of hidden connection to the Dragon Ball universe through his family line. This revelation could change the dynamic of his relationship with Bulma. Or perhaps Bulma accidentally creates a time - traveling device and they end up in a completely different era in either the Naruto or Dragon Ball timeline. This could lead to all sorts of new challenges and opportunities for their relationship, as they have to adapt to the new situation while still maintaining their love for each other.
One possible plot twist could be that Hermione's pureblood status was hidden to protect her from a dark wizard or an old family feud. When the truth comes out, she has to face unexpected enemies.
Well, the plot could start with Anko realizing her feelings for Naruto during a dangerous mission. They gradually fall in love and decide to get married. After marriage, they could be involved in training the next generation of ninja together. Anko's knowledge of more unorthodox jutsus and Naruto's powerful techniques could be combined to create a new training regime. Also, they might have to face off against old enemies who target them because of their relationship and new - found status in the village.
One possible plotline could be that they got married to form an alliance between two powerful factions secretly. Another could be that they fell in love while on a secret mission together that no one else knew about. Maybe Itachi was on a mission to protect Naruto from afar and they developed feelings over time.
A possible plot twist could be that it was all a ruse. Maybe they faked their marriage for some greater good, like to expose a dark wizard who was targeting married wizards. Another could be that one of them was under a spell and didn't really mean to get married secretly, and when the spell is broken, they have to figure out what to do.
One possible plot twist could be that Anko is initially hesitant about the marriage due to her past traumas. Maybe she has some secrets she's afraid to share with Kakashi. For example, her past association with Orochimaru might make her doubt her own worthiness in a relationship. Another plot twist could be external threats to their marriage. The shinobi world is full of danger, and perhaps an enemy targets Anko to get to Kakashi, or vice versa. This could put a strain on their relationship as they try to protect each other while also dealing with the normal stresses of a new marriage.