You can start by looking on fanfiction websites like Archive of Our Own (AO3). There are often tags and filters that can help you narrow down to the specific crossovers between My Hero Academia and Little Witch Academia. Many authors post their creative works there, and you can find a wide variety of stories, from action - packed adventures to heart - warming friendships.
First, know the characters well from both series. Understand their personalities, powers, and backstories. This will help you create believable interactions in your fanfiction. For example, if you're writing about Izuku Midoriya from My Hero Academia meeting Akko from Little Witch Academia, you need to think about how their different outlooks on heroism or magic would play out.
The story mainly follows Akko and her friends in their adventures at Luna Nova. They face various challenges, like dealing with magical mysteries within the Chamber of Time. It's a story full of magic, friendship, and the growth of the young witches as they strive to master their powers and uncover secrets.
Overall, the Little Witch Academia series adheres closely to the manga. Some small tweaks might be made for better visual presentation or narrative flow, but the core elements remain intact.
Another possible theme is self - discovery. The characters may learn new things about themselves or each other while being in this unique 'cuffed together' situation. It could force them to confront their fears, weaknesses, or hidden strengths, and this journey of self - discovery can be a central part of the fanfiction.
One common theme is friendship. Since the characters are locked together, they rely on their friendships to get through the difficult situation. For example, Akko might encourage her friends when they feel down or scared.