Overcoming obstacles is also a big theme. There could be external factors like family or society not approving of their relationship. And they have to fight against these to be together. For instance, in some stories, Ruka's career might be a hindrance to their relationship, but they find a way around it.
Some fanfictions worth checking out are 'Ruka's Dream Date with Hayate'. In this one, Ruka finally gets to go on a date with Hayate and it's full of sweet moments and a bit of awkwardness that makes it very endearing. 'Hayate's Protective Instinct for Ruka' is another. It shows how Hayate starts to feel a strong need to protect Ruka. There are also many fanfictions that explore their relationship in different universes, like a fantasy world where they have to fight together against dark forces and their relationship blossoms during the adventure.
You can try fanfiction.net. It has a large collection of various fanfictions, including those of ruka x hayate. Another place is Archive of Our Own (AO3). It's known for its wide range of fan - created works and has a good number of ruka x hayate stories as well.
Love is a very common theme. Usually, it's about Ruka's love for Hayate or their mutual feelings. Another theme could be friendship. They might start as friends and then develop deeper feelings.
One great place to find hayate x ruka fanfiction is FanFiction.net. There are often many stories there that explore their relationship in various ways, from sweet and fluffy romantic tales to more angsty ones where they face challenges together.
One great 'hayate x ruka fanfic' is 'Hayate and Ruka's Adventure'. It has an interesting plot where they go on a journey together. Another one could be 'Ruka's Feelings for Hayate' which delves deep into Ruka's emotions towards Hayate.
One common theme is loyalty. Hayate is always loyal to Nagi in the series, and this is often explored further in fanfiction. For example, how far he will go to protect her.
One great 'Nagi x Hayate' fanfiction is 'A Chance Encounter'. It beautifully portrays the relationship between Nagi and Hayate, with vivid descriptions of their interactions. The author does an excellent job of showing Nagi's dependence on Hayate in a really heartwarming way.
One common theme could be friendship evolving into something more. Maybe they start as comrades and gradually develop romantic feelings. Another theme might be about facing challenges together, like battling a common enemy while their relationship grows in the process.
In addition to Hayate and Blade, there might be other supporting characters. For example, their comrades or rivals within the story's setting. These characters can add more depth and conflict to the fanfiction. They might be the ones who either help or hinder Hayate and Blade's relationship or their goals.