Well, in this fanfiction scenario, if Naruto discovers Tsunade is his mother, it could change his entire world view. He has always seen Tsunade as a strong and somewhat intimidating figure in the village. Now, as his mother, she could become a more nurturing presence. Naruto might also start to question his own identity more deeply. He's used to being the orphaned Naruto, but now he has a family connection to one of the most powerful people in the village. This could lead to new storylines about him learning more about his family history and what it means to be related to Tsunade.
You can start by looking on fanfiction websites like FanFiction.net or Archive of Our Own (AO3). These platforms have a vast collection of Naruto fanfics and there's a good chance you'll find some where Tsunade plays a significant role.
One possible plot for such a fanfiction is that the squirrel mask has been stolen by an enemy. Minato's spirit appears to Naruto and tells him about the importance of the mask. Tsunade, as the Hokage, organizes a mission to retrieve it. Naruto, with his determination and the help of his friends, embarks on this mission. Along the way, he discovers new abilities within himself that are somehow related to the mask and his father Minato's legacy.
Tsunade's character often develops a stronger sense of purpose. In fanfictions where she finds baby Naruto, she realizes that she has a new mission, which is to raise Naruto to be a great ninja. This might lead to her changing her ways in terms of leadership in the village. She might start to focus more on the future generation and how to make the village a better place for Naruto and others to grow up in. She also may become more empathetic towards others in the village as she experiences the joys and challenges of raising Naruto.
Yes, there are likely some fanfictions out there with such a concept. You can try searching on popular fanfiction websites like Fanfiction.net or Archive of Our Own. Just type in 'Naruto Father of Minato' in the search bar and see what comes up.
The theme of friendship is also quite common. Despite their age difference, Naruto and Tsunade can form a unique friendship. In fanfictions, they might share their past experiences, their hopes and dreams. Tsunade might open up to Naruto about her losses, like the death of her loved ones, and Naruto can comfort her with his positive outlook on life. This friendship can then be a driving force in the story, helping them face various challenges together.
In a fanfic where Tsunade finds a Naruto fanfic, it could be really interesting. Tsunade might be amused or shocked by the different interpretations of Naruto's story. Maybe she'll be intrigued by how the fans see her character. For example, she could find a fanfic that portrays her in a romantic relationship she never expected, and her reaction to that could be quite humorous.
Their relationships could be explored through flashbacks. For instance, we could see how Minato interacted with Tsunade when he was alive. Maybe he sought her advice on certain matters, or they had some joint missions. This would give us insights into their respect for each other.
Naruto could pass on his determination. He's always been someone who doesn't give up easily, and Minato might inherit that. Also, his loyalty. Naruto is extremely loyal to his friends and the village, and Minato could grow up with those values. Maybe even Naruto's love for ramen would be passed on in some comical way.
His relationship with Sakura would change. Sakura has always respected Tsunade as her mentor. Now, if Naruto is Tsunade's son, Sakura might see Naruto in a more complex way, perhaps with a new level of respect. With Kakashi, he might be more protective of Naruto, knowing he's related to Tsunade. And the other villagers, some who have always been a bit standoffish to Naruto, might start to treat him better as they wouldn't want to cross Tsunade.