Luffy will most likely use his Gum - Gum abilities. He could stretch his arms to grab Nami and pull her away from the abuser quickly. For example, he might use Gum - Gum Pistol to knock out the bad guys who are abusing Nami.
In some fanfiction concepts, Luffy could overhear a conversation. Maybe some of the villains are talking about their plans regarding Nami or boasting about how they've been treating her. Luffy, with his excellent hearing skills, picks up on this and figures out that Nami is in a bad situation.
Well, in most cases, Luffy would use his unique abilities. He might use his Gum - Gum Pistol to knock out the bad guys. His superhuman strength and speed would allow him to reach Nami quickly and stop the assailants before any harm could be done. Luffy's sense of justice and loyalty to his crewmates are so strong that he would not let anything bad happen to Nami.
The dynamic between Luffy and Nami is one of the main attractions. Their friendship and loyalty within the Straw Hat crew are well - known, and seeing Luffy come to Nami's rescue emphasizes that bond. It also shows Luffy's heroic side in a very intense situation, which can be quite exciting for readers.
Young Luffy in such a fanfiction would be extremely brave. He'd be the first to rush into danger without thinking twice about his own safety. His loyalty to Nami would be evident as he'd risk everything to save her.
One common theme is friendship. Luffy's act of saving Nami emphasizes the strong bond of friendship within the Straw Hat crew. It shows that they will always look out for one another no matter what.
It could be a group of outcast ninjas who have a grudge against the Hidden Leaf Village. They target Tenten as she is an easy target for them to vent their anger on. They might be jealous of the Hidden Leaf's prosperity and think by abusing Tenten, they can send a message to the village.
Well, one possible plot could be that Tenten is being held captive by some rogue ninjas who are abusing her for information. Naruto, with his strong sense of justice, discovers her situation. He uses his shadow clones to create a distraction and then swoops in to rescue her. Afterward, they form a closer bond and Naruto helps Tenten overcome the trauma of the abuse.
It could be a group of outcast ninjas who have a grudge against Konoha. They see Tenten as an easy target since she is often on solo missions or training alone. These ninjas might be using cruel and unethical methods to try and break her spirit or get some sort of advantage over Konoha.
In this fanfiction, Tenten might be in a mission where she is captured by an enemy village. They are abusing her to get information about Konoha. Naruto, who is out on a search for her, uses his shadow clones to infiltrate the enemy base. Once he finds Tenten, he battles the captors. His unwavering determination and the power of the Nine - Tails' chakra help him defeat them all. He then rescues Tenten and they make their way back to Konoha together, with Tenten being very grateful to Naruto for saving her.