No, they don't. The relationship between Yona and Hak in the manga doesn't involve a kiss.
Yes, they do. Their relationship develops throughout the manga and eventually leads to them being together.
Yes, they do. The manga concludes with Hak and Yona ending up together and finding happiness.
Definitely. Throughout the manga, it's clear that Yona's love for Hak grows and becomes an important aspect of the story. Their relationship develops in various ways that show her affection for him.
You can try Archive of Our Own (AO3). It has a large collection of fanfictions, and you're likely to find many yona and hak kiss fanfictions there. Just use the search bar and type in the relevant tags.
There's a fanfiction titled 'Under the Starry Sky'. In this story, the build - up to their kiss is filled with so much emotion and longing. The author does an amazing job of showing how their feelings for each other have developed over time before that kiss moment. It's quite a heartwarming read.
One common theme is adventure. Since the original story has a lot of adventure elements, fanfics often continue this. Yona and Hak go on quests together, facing enemies and exploring new lands, which strengthens their bond.
Maybe in the fanfiction, Yona gets pregnant unexpectedly. At first, they are both shocked but then filled with joy. Hak starts building a small house for them to live in. They go through the normal pregnancy experiences like Yona having cravings and Hak trying his best to fulfill them. Their friends also rally around them, offering support and advice for the upcoming new life.
A common characteristic is the strong emphasis on their loyalty to each other. In these fanfics, Hak is always by Yona's side, protecting her no matter what. Yona also shows her trust in Hak.
Another theme is growth. Yona's growth as a person and a leader is often intertwined with her relationship with Hak. As she becomes stronger, their love also evolves. In some fanfictions, it's shown how this growth brings them closer and makes their bond even deeper.
One popular 'Yona of the Dawn Yona x Hak fanfic' is 'The Journey Ahead' which beautifully explores their relationship as they face various challenges together. It has great character development and a lot of sweet moments between Yona and Hak.