One popular theme is the exploration of their relationship development. It could be how they first meet in different scenarios than in the original work and how their feelings gradually change over time.
One great Shimoneta Tanukichi x Ayame fanfiction could be about their adventures in a world where their relationship is more openly accepted. It might explore how they deal with daily life together, facing the unique challenges of a relationship in a society that was once so restrictive.
Fanfiction.net is also a popular place. However, the interface might be a bit more cluttered compared to AO3. But it still has a wide range of fanfictions, including ones related to Shimoneta. You might need to dig a bit deeper and use relevant tags to find the Tanukichi x Ayame ones.
You can try searching on popular fanfiction websites like Archive of Our Own (AO3). It has a large collection of fanfictions from various fandoms, and there's a good chance you'll find some great tanukichi x ayame fanfiction there.
The theme of mutual support is also quite common. Naruto is often shown getting support from Ayame, whether it's emotional or practical. And in return, Naruto's presence in Ayame's life gives her a new perspective. For instance, Naruto's tales of his adventures might inspire Ayame to be more adventurous in her own life, like trying new recipes inspired by the places Naruto has been to.
Often, you'll see the theme of Ayame being the one who understands Naruto on a different level. Maybe she's the one who can see past his boisterous ninja side and get to the real Naruto. There's also the theme of how their relationship affects the community around them. For example, how Naruto's friends react to him being interested in Ayame and vice versa. And sometimes, there's the theme of self - discovery through their relationship. Naruto might learn more about himself and his desires outside of being a ninja through his connection with Ayame.
In many 'Naruto x Ayame Harem' fanfictions (without lemon), there are themes related to loyalty. The characters in the harem are often loyal to Naruto and to each other. There can be themes of cultural exploration too, as Naruto's world has a rich and diverse culture. For instance, they might explore different ninja clans' cultures together. And lastly, the theme of redemption. A character might have a past mistake or regret and through the relationships in the harem, they find a way to redeem themselves.
One common theme is friendship. Given Naruto's friendly nature and Ayame being a part of the village, their friendship is often explored. Another theme is growth. Naruto is constantly growing as a ninja and Ayame can be shown to grow in her own way, perhaps in her understanding of the ninja world.
There's a fanfic titled 'Ayame's Influence on Naruto'. In this, Ayame helps Naruto with his training in a different way, perhaps through cooking and providing him with special meals that enhance his strength. She also gives him emotional support and advice, which changes the way Naruto approaches his ninja life.
One common theme is the overcoming of obstacles. Since Naruto has his ninja duties and Ayame has her life in the village, they might face challenges in getting together. Another theme could be the discovery of new feelings, as Naruto might not have initially thought of Ayame in a romantic way.
One common theme is the 'unlikely love' aspect. Since Naruto is a famous ninja and Ayame is a simple ramen shop owner, their different lifestyles create an interesting contrast. Another theme is the 'growth' theme, where Naruto's growth as a ninja and a person is intertwined with his relationship with Ayame. As he matures, his feelings for her also develop.