One common theme is time - often Hermione travels back in time to meet young Sirius. Another theme is friendship. Since they are from different generations in the wizarding world, their friendship is an interesting exploration. For example, they might share knowledge about magic that the other doesn't know.
One popular 'young Sirius and Hermione fanfiction' is 'Time Traveler's Daughter'. It has an interesting plot where Hermione goes back in time and meets a young Sirius. Their interactions are full of mystery and a bit of budding friendship. It also delves into the complex wizarding world politics of that time.
One popular story might be 'Forbidden Bonds' which explores a unique relationship between them. It delves deep into their characters and how they might interact in a different way than in the original series. The author creates a lot of tension and drama, making it an engaging read.
Often, it begins with Hermione trying to help Sirius deal with his post - Azkaban trauma. She uses her knowledge and compassion to reach out to him. As he heals, he starts to see her in a new light. Their relationship then grows as they start to understand each other better. The lemon parts usually are used to explore their more passionate and private moments, which are often written in a very tender and intense way, adding a new dimension to their relationship.
The contrast between their personalities. Sirius is wild and impulsive, while Hermione is studious and cautious. When combined in fanfiction, it creates an interesting dynamic.
There are quite a few good ones. For example, some focus on Sirius mentoring Hermione in the ways of the wizarding world outside of what she learned at school. This could include knowledge about the Marauders' era and secrets of Hogwarts that were long forgotten. The chemistry between their characters can be really interesting to read about in these fanfictions.
In a Hermione and Sirius family fanfiction, Hermione might end up marrying into the Black family. Since Sirius was an important part of the Black family before his estrangement, Hermione could find herself involved in the family's complex politics and traditions. She could use her knowledge of magic and her Muggle - born perspective to challenge some of the old - fashioned ideas within the family. Sirius, on the other hand, could be like a mentor to Hermione, teaching her about the more secretive and dangerous aspects of the wizarding world that she might not have known otherwise.
One possibility could be that Sirius sees Hermione's intelligence and determination and decides to take her under his wing. Maybe he realizes her potential and wants to protect her from the dangers in the wizarding world that he has faced himself.
There could be a fascination with power dynamics. Sirius is an older and more experienced wizard in the Harry Potter world compared to Hermione. Fanfic writers may be drawn to the idea of how his knowledge and power could interact with Hermione's intelligence and determination, thus leading to the concept of him dominating in the fanfiction. Also, it might add an element of unexpectedness or novelty to the relationship between two such different characters.
If you're looking for a fanfiction with this specific scenario, you could try using more detailed search terms. For example, include the Hogwarts house Hermione belongs to in the search, or any specific events that might be related to it. Also, look for tags on fanfiction platforms that might lead you to the story you want. There are often tags for characters, locations, and relationships which can help narrow down the search.