Itachi would probably be very calm and composed. He might see Sarada as a symbol of the new generation of ninjas in the village. He could be gentle with her, perhaps sensing her potential and her desire to grow as a ninja.
Sarada might be initially shocked and sad. She loves both her parents, and the divorce would be a huge blow to her. She could become withdrawn for a while, not wanting to talk to her friends about it.
Sasuke would be deeply affected. He and Naruto had a complex relationship, from being rivals to friends. He would likely feel a sense of guilt, as if he should have been there to protect Naruto. Sakura would be heartbroken. She had always cared for Naruto, and seeing him die in such a tragic way in front of his parents would make her feel helpless. His parents, on the other hand, would be in utter despair. His father might feel like he failed as a father again, not being able to protect his son this time either.
Naruto would probably be overjoyed at first. After all, he has always longed for his parents. But with the sister, it might be a bit more complicated. He might be a bit cautious, not sure how to interact with her at first. But eventually, he would welcome her into his life with open arms.
Naruto may also try to find solutions. Despite the heartbreak, his optimistic nature might still shine through a bit. He could start to search for ways to mend the relationship with his parents, whether it's through magic in the Naruto world or by trying to prove his worth to them.
Sakura would be a great addition. As Sarada's mother, she could add an interesting dynamic. Also, Boruto could be included. His relationship with Sarada and his own skills could create some engaging storylines. Another good character could be Kakashi. His wisdom and combat experience could be useful in the story.
Naruto's influence would likely make Sarada more determined. His never - give - up attitude is infectious. So, Sarada might face challenges with more tenacity.
At first, Naruto might be a bit hesitant. He's not used to having something so personal from his parents. But then, his curiosity would get the better of him, and he would slowly unroll the scrolls, his hands trembling slightly as he realizes that he's about to learn things he has always dreamed of knowing about his parents.
Minato and Kushina would likely have a complex reaction. They would be proud of Naruto's heroic deeds in fanfiction. But if they saw him being in danger or having a hard time, they would be worried. Also, if there are parts where Naruto's values seem different from what they taught him, they might be a bit confused.