A common theme is rivalry. Since they are often pitted against each other in the original context, fanfics play on this dynamic, showing how their competition can also be a form of connection.
I've heard of 'The Yumeko - Mary Encounter'. It begins with a chance encounter between them and then explores how their personalities clash and yet also complement each other, leading to a unique and engaging story.
Sure is! Kakegurui originated as a manga and has since been adapted into various forms like anime and live-action series. The manga provides the foundation for these other adaptations.
Kakegurui manga is definitely worth a read. It offers a fresh take on gambling-themed stories, and the tension and drama are maintained throughout. The visuals and the writing work together seamlessly to create an immersive experience.