Yes, there are some. You can start by looking on fanfiction platforms like Archive of Our Own. There are often many works created by fans who are inspired by the relationship between these characters.
Archive of Our Own is a great place to start. It has a large collection of fanfics from various fandoms, including alice nine. Just use the search function and type in 'alice nine tora x shou' and you should get some results.
The relationship could develop through shared experiences. For instance, Naruto and Tora could get lost in a mysterious part of the village that is filled with ancient ninja traps. As they work together to escape, they learn about each other's strengths and weaknesses. Tora might be small but is very agile, and Naruto has his brute strength and ninja skills. By relying on each other, their relationship becomes stronger and more meaningful.
One common theme is friendship. Ushio and Tora have a very special bond, and many fanfictions explore how this friendship grows and endures through different situations. Another theme is adventure. They often go on various quests in the original work, and fanfictions expand on these adventures.
One idea could be that Tora has some sort of special power that Naruto discovers. For example, Tora might be able to sense chakra in a unique way and help Naruto track down enemies. Another idea is a story where Naruto and Tora go on an adventure together in the forest outside Konoha. Tora could get lost and Naruto has to use his ninja skills to find him, all while facing various forest creatures and obstacles.
Often, Saga x Shou fanfiction focuses on their unique bond. It might show how they complement each other, like Saga's strength and Shou's intelligence working together.
One great ushio x tora fanfiction is 'The Bond Beyond Worlds'. It beautifully explores their relationship in a world where they have to face new and unexpected challenges together. The way the author describes their interactions is really engaging.
A common theme could be friendship development. Since they have an interesting dynamic, many fanfictions might explore how their friendship grows deeper.
One prevalent theme is the exploration of Tora's character through his relationship with the OC. It could be about how the OC helps Tora grow or change in some way. Also, themes of friendship and loyalty are quite common. The OC and Tora might face challenges that test their bond, and how they overcome those challenges is often part of the story.
One popular 'poppi x tora fanfic' could be 'The Adventure of Poppi and Tora' which focuses on their friendship. It has great character development and an engaging plot.