Rin could also be an important character. She could be the one who takes care of baby Naruto's day - to - day needs, like feeding and cleaning. She could also have a special bond with Naruto, perhaps seeing him as a symbol of hope for the future of the village.
There could be Sasuke. Since Sasuke is Naruto's rival and often involved in the same major story arcs, he might play an important role in this fanfiction. His sharingan abilities could interact with Naruto's newfound speed in some interesting ways, either as an ally or an obstacle depending on the plot.
Sakura could be another main character. She might be shocked by Naruto's arrest and start her own investigation. Maybe she teams up with Sasuke, who also has his own complex feelings towards Naruto. Their combined efforts could play an important role in uncovering the truth.
Jiraiya is likely to be a popular character. He was Minato's teacher and has a strong influence on Naruto as well. In a time travel fanfiction, he could provide a lot of wisdom and help in the different situations they encounter. Also, Tsunade could be important. Her leadership skills and medical ninjutsu could be very useful when they are in the past, and she has her own history with both Minato and Naruto's family.
One possible plot could be about Minato's team training baby Naruto. Maybe they teach him basic ninja skills early on, like how to throw a kunai accurately. This could also involve some heartwarming moments between Minato and Naruto as father - son, with the team members looking on fondly.
Kushina could be an important character even though she's dead in the original story. In this fanfic, her spirit or memories could play a role in Naruto's upbringing. For example, Minato could tell Naruto stories about Kushina's feisty personality and her love for the village.
The key characters are obviously Naruto himself and the members of Team Minato. Team Minato consists of Minato Namikaze (Naruto's father), Kakashi Hatake, Rin Nohara, and Obito Uchiha. Naruto is the main character from the original series who travels back in time or through some other means to meet his father's team.
He uses his skills as a ninja to protect Naruto. He sets up special seals around Naruto's crib to keep out any potential threats. Also, Minato might try to use his chakra to boost Naruto's weak body. He would transfer his own life force a little bit at a time to help Naruto fight the sickness, which is a huge sign of his love.
It could be Danzo. He might have some hidden motives and manipulate situations to make Naruto look like a threat, forcing Minato to arrest him.
Perhaps an ancient evil that was sealed away long ago is awakened when Minato is revived. This entity could be a powerful demon or a dark ninja from the past. It wants to destroy the ninja world and Minato stands in its way. Minato, with his skills and knowledge, has to figure out how to defeat this ancient evil with the help of Naruto and the other Leaf Village ninjas.
Perhaps a new and original antagonist could be created for this fanfiction. This antagonist could be a rogue ninja who has mastered a forbidden jutsu that allows him to manipulate time as well. He could be the one who sets up the events that lead to Minato's endangerment, and Naruto has to figure out his motives and stop him while also saving Minato.