Maybe the deaf character has a dream, like becoming a dancer. Shouya supports the dream and they start training together. However, they face many setbacks because of the deaf character's disability. But with Shouya's determination and the deaf character's passion, they find ways to work around the problems. This could be a story about chasing dreams against all odds.
Another idea is that the deaf character is being bullied because of their disability. Shouya steps in to protect them. As a result, they become closer friends. Shouya then tries to raise awareness about deafness in their school and community, which is not easy as there are a lot of misunderstandings. But through their friendship, they slowly start to change people's perspectives.
In this fanfiction, the deaf character could be a new student at Shouya's school. Shouya, having had his own experiences of being an outcast, feels a connection and decides to befriend the deaf student. They face challenges together, like dealing with bullies who don't understand the deaf student's situation. Through their friendship, Shouya also grows as a person and learns more about empathy.
A fanfic could center around a trip they take together. They could go to a beautiful beach. Shouko would be excited to see the ocean for the first time, and Shouya would be there to make sure she has a great time. They might build sandcastles and collect seashells, and this simple trip could strengthen their relationship even more.
A unique plot is also important. Instead of just rehashing the events of the movie, the fanfiction could take the characters in a new direction. For instance, what if Shouko and Shouya were transported to a different world? How would they interact and survive in that new environment? This kind of creative plot can make a fanfiction stand out.
In a fanfic, their relationship could be explored in a more magical setting. For example, they find themselves in a world where they can communicate without words, just through emotions. This would enhance their bond as they already have a deep understanding of each other. Shouko's gentle nature and Shouya's determination would shine in this unique world.
It could focus on their daily lives and how they find joy and meaning in the simplest things. Or, it could involve a trip that leads to self-discovery for both. Also, there might be conflicts with other characters that bring out their protective sides for each other.
Fanfiction.net is also a great place to search. Some writers may post their works about these two characters there. However, the quality can vary more compared to AO3. You need to read the reviews and summaries to find the good ones.
It could add a whole new layer of complexity and empathy to the story. Maybe it would change how he interacts with others and how they perceive him.
A great Silent Voice fanfic idea could be a time - skip story. Imagine what the characters' lives are like years after the events of the movie. Have Shoya and Shoko stayed together? What about their careers? Maybe Shoya has become a sign language teacher, and Shoko is an artist. Or perhaps write a fanfic where a new character enters their lives, someone who doesn't know about their past but slowly uncovers it and helps them heal old wounds in new ways. You could also do a fanfic that's centered around the school events but with a magical twist, like a magical object that helps Shoko communicate more easily and changes the dynamics between the characters.
Create conflict within the character interactions. If 'A Silent Voice' is crossed over with 'Attack on Titan', Shoya might not understand the brutal world of the Titans at first. His more peaceful nature could clash with the survival - instinct - driven characters in 'Attack on Titan'. This conflict can lead to interesting conversations and growth for both sets of characters as they try to understand each other's worlds and values.
Hard to say for sure. It depends on the author and publisher's decisions.