He could find his father's old Hokage cloak. It would be a significant discovery as it represents his father's important role in the village.
Iruka could play a role. He was Naruto's first teacher who believed in him. He might have some small piece of information that starts Naruto on his journey to find his parents. Then there's Tsunade. As the Hokage, she has access to a lot of secret files. She could either be an obstacle, not wanting Naruto to dig too deep, or she could be a helper, providing him with crucial information. And of course, the Nine - Tailed Fox. It was sealed inside Naruto by his father, so it might have some memories or knowledge related to Naruto's parents that it could share with Naruto.
The house might hold the truth about Naruto's birth. There could be records or something that reveals more about the circumstances of his birth, like why he was chosen to be the Jinchuriki of the Nine - Tails. This would be a huge revelation for Naruto.
He might find mementos of his parents. Maybe he'll come across old photos or letters that reveal more about their lives. This could give him a stronger connection to his heritage and a deeper understanding of who his parents were.
He might find old mementos of his parents. Maybe a photo album that shows their life before he was born. It could be filled with pictures of his father's training days and his mother's gentle smiles. This discovery could give Naruto a deeper understanding of his family's history and make him feel more connected to them.
He could uncover the truth about his father's real mission before he died. Maybe it was something that was kept hidden from the village for some reason.
One possibility could be a time-travel fic where Naruto goes back and meets his parents before their deaths.
In the fanfiction, the scrolls could reveal a lot. For example, they might disclose the circumstances of Naruto's birth. Maybe there are prophecies written in them about Naruto's future. There could be stories of his parents' love and how they made sacrifices for the village and for Naruto. It could also be that the scrolls contain some sort of training method that was unique to his family, which would help Naruto become even stronger as a ninja.
Naruto might initially be angry and shout for someone to let him out. He has a strong will and doesn't like being confined. But as time goes on, he could become more creative. He might start to communicate with his friends secretly through some ninja means, like sending messages via small animals. He would also likely be thinking about how to prove his innocence if that's the reason for his confinement. He's not the type to just sit around and accept an unjust situation.
Emotionally, Naruto would have to deal with a whole new set of family relationships. He grew up without his parents, and now having them back would be a huge adjustment. He might struggle to fit into a 'normal' family dynamic, and there could be some friction as they all get to know each other again.
On a personal level, Naruto would finally get the family he always wanted. But it might also bring some confusion and adjustment issues. His parents would be from a different time, and they'd need to adapt to the new world Naruto lives in. For example, they might be shocked by the new technology and the changes in ninja warfare.