One of the main themes is adventure. Since rengoku is often involved in battles and dangerous situations, the fanfics may take the reader along on these adventures. They might face demons together and their relationship develops through these shared experiences. Also, loyalty is a big theme. Rengoku is a very loyal character, and this loyalty extends to his relationship with the reader in the fanfics.
Well, some popular rengoku x reader fanfics can be found on Wattpad as well. Look for ones with high ratings and good reviews. They usually offer different storylines, from adventure - filled ones where rengoku and the reader go on quests together, to more romantic and heart - warming stories about their relationship.
One popular theme could be friendship exploration. Since Cuddles and Giggles are characters, their relationship in fanfiction might focus on how they become better friends, like going on adventures together in the forest. Another theme could be problem - solving. Maybe they face a big issue in their little world and have to work together to solve it. For example, a flood might come and they need to find a way to save their friends.
One common theme is adventure. Since both characters are from the Demon Slayer universe, they often go on demon - slaying adventures together in the fanfictions. They might face powerful demons and rely on each other's skills to survive.
You can start by looking on fanfiction websites like Archive of Our Own (AO3). It has a large collection of fan - created works, and you can use the search function to specifically look for Cuddles x Giggles fanfiction. Another option is FanFiction.net. There are many users who post their stories there, and you might find some interesting ones about these characters.
You can try fanfiction platforms like Archive of Our Own (AO3). There are a large number of fan-created works there. Just use the search function and type in 'female Tanjiro x Rengoku' and you'll likely find a variety of stories with different themes and writing styles.