Often, they might face challenges together. For example, in the context of the My Hero Academia universe, they could be fighting villains side by side and that experience strengthens their bond. And their different quirks might play an interesting role in how they interact and support each other during these situations.
Another theme could be self - discovery. Both characters are on their own journey of growth in the original series. In the fanfiction, their relationship can be a catalyst for them to discover new aspects of themselves, like Deku learning more about his own emotions and Shinshou (as a female in this case) understanding her place in the world and her relationships better.
A common theme is probably the development of their relationship. It could start from friendship and gradually turn into something more romantic.
One place to find such fanfiction could be Archive of Our Own (AO3). Just search for 'female shinshou x deku' on their site and you'll likely come across various works.
One common theme is redemption. Bakugou, who was often a bully in the original story, has a chance to redeem himself in his relationship with female Deku. For example, in many fanfictions, he realizes his past mistakes and tries to make it up to her.
One common theme is the exploration of gender - how being female changes Deku's approach to Kacchan. For example, it might add a new layer of emotional vulnerability.
Common themes include the exploration of their individual insecurities. For female deku, it might be about not being strong enough at first, and for todoroki, his family issues. As they come together, they help each other deal with these. Also, the theme of finding a true connection in a world full of chaos is often there. Their relationship becomes a sort of haven in the midst of all the hero - related chaos. There's also the theme of acceptance, accepting each other's flaws and strengths.
One common theme is growth. Both characters often grow as individuals and in their relationship. For example, they might learn to overcome their insecurities or past rivalries. Another theme is the power of friendship evolving into love. They start as classmates or rivals, and then their bond deepens into something more romantic.
Friendship is a very common theme. Given their different backgrounds and personalities, seeing how they become friends and support each other is often explored. For example, female Todoroki may come from a more troubled family situation compared to the optimistic female Deku, and their friendship can be a source of healing for both.
One common theme is the exploration of their complex relationship. Since in the original they have a very intense and somewhat combative relationship, in fanfiction it often turns into a more romantic and understanding one. Another theme is growth. They both grow as individuals and as a couple, learning from each other's strengths and weaknesses.
One common theme is empowerment. Female Deku is often shown as a strong and capable hero, breaking gender barriers in the My Hero Academia universe.
One common theme is mutual growth. They both inspire each other to become better heroes. For example, Deku's determination might push Iida to be more fearless, and Iida's sense of order and discipline can influence Deku to be more organized in his hero training. Another theme is friendship - turned - romance. Usually, they start as friends and classmates, and then as they get to know each other better, romantic feelings develop.
Growth and support is also a frequent theme. Deku is constantly growing as a hero, and Tsuyu is there to support him in many fanfictions. It could be emotional support during tough times or helping each other in battles, which then leads to a deeper connection between them.