It could be that Naruto is sent to prison as part of a political move. There are some ninja clans within the village who are jealous of his popularity and influence. They conspire to get him out of the way by making it seem like he's a threat to the village's security. In prison, Naruto discovers a hidden conspiracy within the prison walls that is related to the outside political turmoil and he has to find a way to expose it while also getting himself released.
One possible plot could be that Naruto is wrongly accused of a crime he didn't commit. Maybe he was framed by an old enemy who wants to see him suffer. While in prison, he tries to prove his innocence. He could use his ninja skills subtly to gather evidence within the prison walls, and also make some unlikely allies among the inmates who start to believe in his innocence as they get to know him better.
One possible plot twist could be that Naruto discovers a hidden conspiracy within the Blood Prison. Maybe the prison is being used for something more sinister than just holding criminals. Another twist could be that Naruto's friends believe he's a traitor for ending up in such a place and he has to prove his innocence to them while still trapped in the prison.
The main antagonist could be a rogue ninja who has infiltrated the village's council. This ninja could be secretly manipulating things behind the scenes to get Naruto sent to prison. He might have a vendetta against Naruto for some past encounter or just see him as a threat to his own evil plans.
One possible plot could be that Naruto is framed for a crime he didn't commit. Maybe someone with a vendetta against him plants false evidence. In prison, he would have to deal with tough inmates and the strict prison regime while trying to prove his innocence.
In a 'naruto keeped in prison' fanfic, it could start with Naruto being framed for a crime he didn't commit by a mysterious enemy. Inside the prison, he faces all kinds of hardships. However, he uses his unique ninja skills, like his shadow clones in a very discreet way, to gather information. He could also form an alliance with other inmates who have different skills. Eventually, he uncovers the real culprit behind his imprisonment and clears his name while also making the village a safer place by revealing a hidden threat.
He could use his transformation jutsu. He could transform into a guard or an inmate who has access to the prison exit areas. Then he could just walk out when the opportunity arises.
In this situation, Naruto could also use his ninja skills in a discreet way. For example, he could use his shadow clone jutsu to gather information without being noticed. He might discover that the ones who framed him are actually part of a larger conspiracy against the Hidden Leaf Village. So, his main goal would then not only be to get out of prison but also to expose this conspiracy.
One possibility is that Naruto's unique ninja skills would make him a very powerful adventurer in WoW. His ability to use chakra could be translated into some kind of magic or special combat ability. For example, his Shadow Clone Jutsu could be used to confuse enemies or complete multiple quests simultaneously.
Maybe he discovers some dark secrets in the Blood Prison. These secrets could be about the corruption of the ninja world or some hidden evils related to powerful people. This new knowledge might make him lose faith in the system he once believed in, leading to his transformation into a darker version of himself.
Well, one possibility could be that Naruto is wrongly accused of a crime in the Hidden Leaf Village and is sent to prison. There, he might meet other prisoners with unique abilities or stories. He could use his ninja skills in a different way, like trying to maintain peace among the inmates. Maybe he'd also be planning his escape while uncovering the real truth behind his false accusation.