The dog's behavior should be based on real dog traits. For example, it could be very loyal to the Avengers. It might also have a love for chasing things, which could lead to some comical or even plot - relevant situations. It should also show fear or caution in dangerous situations, like when facing a powerful villain.
The relationship can start with Kakashi noticing the student's potential. He might give the student more challenging tasks and offer advice. Over time, as they spend more time together during training and missions, they start to understand each other on a deeper level. For example, the student could share their dreams and fears with Kakashi, and he could open up about his past experiences, gradually building a bond.
She could be developed as a kind - hearted person. Since the dog licked her, she could show compassion towards it by taking it to a vet if it seems unwell or by sharing her food with it. This would show her nurturing side. Also, her reaction to the lick can be used to show her personality. If she laughs it off, she might be easy - going. If she gets scared at first but then warms up, it could show her as cautious but open - minded.
Maybe the dog reader is from another dimension. It accidentally ends up in the Avengers' world. At first, the Avengers are confused but then realize the dog is actually quite intelligent. It can communicate in its own way, perhaps through telepathy with some of the more magically - inclined Avengers like Scarlet Witch. They then try to find a way to send the dog back home while also using its abilities to help them fight villains.
For a realistic relationship development, communication is key. They need to openly talk about their differences, like how Hobbits' love for home and gardens might seem strange to a more adventurous human. Shared experiences also matter. If they go through a difficult battle or a challenging journey together, it can bring them closer. And they should respect each other's boundaries. For example, a Hobbit's need for a certain amount of alone time in their cozy hole should be respected by the human.
For the military medic, show his training and the toll that the military life takes on him. Maybe he has nightmares about the wounded he couldn't save. For the girl reader, give her a backstory that makes her unique. If she's in a war - torn area, show how she copes with the daily hardships.
I'm not entirely sure specifically what 'x dog reader fanfiction' is about without more context. It could be fan - created stories that involve a dog and are written for readers, perhaps with an 'x' factor which could be anything from a unique setting, a special ability of the dog, or a particular genre it belongs to.
A realistic relationship development between Kakashi and the male reader can be achieved by showing their growth as individuals while they are getting closer. For instance, if the male reader is initially a shy person, he could gain confidence through Kakashi's support and training. Kakashi, on the other hand, could become more open and less guarded as he spends time with the male reader. They should also have normal disagreements, like about how to handle a mission situation. Resolving these differences in a healthy way will strengthen their relationship and make it seem more real.
It can start with mutual curiosity. The Doctor is intrigued by the reader's unique perspective or skills, and the reader is fascinated by the Doctor's otherworldly nature. Then, through shared adventures, they start to trust each other more.
For a realistic relationship development, it should start with mutual respect. Even if they are initially on different sides, they need to recognize each other's strengths. For example, the reader might admire Jake's survival skills in the desert. Then, through shared experiences like facing a common enemy or surviving a sandstorm together, their bond can grow. Communication is also key. They need to be able to talk to each other, understand each other's motives and fears.
You can try looking on fanfiction websites like Archive of Our Own (AO3) or FanFiction.net. They have a wide variety of fan - created stories, and you might be able to find 'x dog reader fanfiction' there by using the search function.