Daphne could be a shy and artistic girl. She might be into painting or writing, and she sees Harry as this source of inspiration. Maybe she first noticed Harry in an art gallery or a library, and that's when the crush started.
One great 'Harry Daphne Fanfic' is 'The Green-Eyed Snake'. It has a really interesting plot where Daphne and Harry team up to solve a mystery in the wizarding world. Their relationship develops in a very natural way throughout the story.
In this fanfic, Harry would likely grow in his social skills. Since Daphne has different social circles, he'd be introduced to new people and ways of interacting. He might become more diplomatic, learning from Daphne how to handle different personalities gracefully. Daphne would develop a stronger sense of loyalty. As she gets to know Harry better, she'd see his unwavering loyalty to his friends and causes, and this would inspire her. She might also become more adventurous, as Harry often gets into exciting (and sometimes dangerous) situations, and she'd be drawn into them, expanding her own boundaries.
Hermione would probably be in it. Since she's Harry's best friend, she might offer her intelligence and advice to Harry and Daphne in their post - war endeavors. Maybe she helps them with research or legal matters if they're trying to change things in the wizarding world.
Their relationship could be one of mutual protection. Harry, with his heroic nature, would always be ready to defend Daphne. And Daphne, being intelligent and resourceful, could offer her own kind of support to Harry, like helping him with his studies or providing advice in tricky situations.
There are probably some. For example, they could be written in a way that they are partners in solving a mystery within the wizarding world. Their relationship could be portrayed as a platonic one where they respect and support each other in achieving common goals.
One possibility could be that in the fanfic, Harry and Daphne meet by chance at the Yule Ball. Maybe Daphne is initially hesitant to interact with Harry as he is a Gryffindor, but as they start dancing, they find themselves drawn to each other. They start sharing stories about their Hogwarts experiences, from difficult classes to dealing with the various creatures around the castle. Harry might be surprised by Daphne's intelligence and grace, and Daphne could be intrigued by Harry's courage and his tales of facing Voldemort.
There's this fanfic called 'Harry, Daphne and Astoria: Bonds Beyond Houses'. It shows how their different house allegiances don't matter when they come together. It delves deep into their personalities and how they support each other through different challenges at Hogwarts, which is really refreshing.
I really like 'Harry and Daphne's Unlikely Alliance'. In this fanfic, it shows how Harry and Daphne come together in a world full of challenges. There are great descriptions of Hogwarts and the relationships between different characters in the harem. It's a great read for those who enjoy this type of fanfic.
One common theme is friendship. They often start as friends or comrades in the fanfics. For example, in many stories, they bond over a shared interest in a particular area of magic.