They could develop their relationship through letters. For example, if the soldier is deployed overseas, the schoolgirl could write to him as part of a school initiative to support the troops. Through these letters, they learn about each other's worlds, dreams, and fears, and gradually fall in love.
Through shared memories. Since they both have a complex past, they could start by sharing some of their most painful or formative memories. For example, the Winter Soldier could talk about his time being brainwashed and Black Widow could share about her time in the Red Room. This would create a sense of understanding and closeness between them.
In the fanfiction, the army soldier could be injured and is sent to a local hospital near the school. The schoolgirl volunteers at the hospital and they cross paths. She is in awe of his sacrifice and he is touched by her kindness. This encounter leads to a series of events where they get to know each other better and develop a special bond.
Communication is key. In the fanfiction, they could have deep conversations about their dreams, fears, and past traumas. Laslow might share his experiences as a wandering mercenary, and Corrin could talk about her complex family situation. Through these exchanges, they would understand each other better and draw closer. Another aspect could be through acts of self - sacrifice. If one of them is in danger and the other risks their life to save them, it would strengthen their bond significantly.
Another way is through sacrifice. If Orihime sacrifices something important for the sake of an Espada, or vice versa, it can deepen their relationship. This act of selflessness can show the depth of their feelings for each other and be a turning point in their relationship within the fanfiction.
The relationship can be developed through shared experiences. For example, they could go on a joint mission to retrieve an important artifact. During this mission, they face various challenges together, which helps them bond. They might have to trust each other with their lives, and this deepens their connection.
By showing them having heart - to - heart conversations. For example, they could talk about their experiences growing up as demigods, their fears, and their hopes. This would deepen their connection.
By creating more shared experiences. For example, they could go on a journey together to find a special item or to help someone. During this journey, they would face challenges and have to rely on each other, which would strengthen their bond.
The relationship can be developed through shared missions. When they are on a mission together, they can rely on each other's skills and learn from one another. For example, Naruto's vast combat experience can help Sarada in tough battles, and Sarada's fresh perspective can give Naruto new ideas.
In fanfiction, their relationship can be developed through shared experiences. For example, they could be trapped in a mysterious dimension together. During their time there, they have to rely on each other to survive, which makes them trust one another more.
In a fanfiction, a common goal can bring them together. Say there is a powerful, evil Pokémon that is threatening their habitats. Houndoom and Ninetales, despite their differences, realize they need to combine their strengths to defeat this foe. As they plan and fight together, they start to respect and care for each other more. This shared experience becomes the foundation of their relationship.