One common theme could be friendship. Haru and the pool setting might be used to show the development of a deep friendship between characters.
Friendship is a common theme. Baron and Haru often form a deep bond in fanfics, supporting each other through different situations.
One common theme is friendship development. Their relationship might start as just acquaintances and gradually grow into a deep and meaningful friendship.
One common theme is friendship turned into something more. They start as friends or acquaintances and then develop deeper feelings for each other.
One common theme could be transformation. Haru might transform in relation to water, like becoming more powerful when in contact with it.
One common theme is the exploration of their contrasting personalities. Shizuku's calmness against Haru's wildness makes for interesting character dynamics. Another theme is friendship or the development of a deeper relationship, like love.
Overcoming obstacles together is also a frequent theme. They might face external threats or misunderstandings. In some fanfics, there are rival characters who try to come between them, but Tsuna and Haru always find a way to overcome these difficulties and strengthen their bond in the process.
One common theme is friendship. Many fanfics explore how their initial friendship blossoms into something deeper. Another theme is self - discovery. As they interact more, both Haru and Rin often discover new things about themselves.
Love and friendship are common themes. Since they are characters from the same series, their relationship can be explored in terms of how a friendship can turn into something more. Also, growth is a theme. For example, Tsuna might grow more confident in his relationship with Haru, and Haru might grow more independent while still being close to Tsuna.
I'm not sure about specific 'haru x pool fanfic' stories offhand. You could try searching on fanfic platforms like Archive of Our Own. They usually have a wide variety of fan - created works.
One common theme is friendship. Haru and the reader often start as strangers and develop a deep friendship through shared experiences. Another theme is adventure. They might go on quests or travels together, exploring new places and facing challenges. Growth is also a theme, as both characters usually grow and change as a result of their relationship with each other.