You can try fanfiction.net. It has a large collection of various fanfics, including those related to 'joker x haru'. Another good place is Archive of Our Own (AO3). They have a wide range of fan - created content, and you're likely to find some great 'joker x haru' stories there.
Well, 'joker x haru fanfic' often varies in theme. Some might be interested in 'Shadows of Redemption', where Joker helps Haru overcome her inner demons. Then there's 'The Red Thread' which is a beautifully written fanfic about their fated encounter. Also, 'Haru's Choice' is quite interesting as it shows Haru making difficult decisions with Joker by her side.
One characteristic is the exploration of their relationship dynamics. Since they are two different characters, the fanfic often shows how they interact, whether it's friendly banter or deeper emotional exchanges.
Friendship is a very common theme. Writers often explore how the deep bond between Rin, Haru, and Makoto affects their lives. For example, they might write about how they support each other through tough times in school or in their swimming careers.
I'm not sure specifically about lemon fanfiction involving them as it often goes against the general family - friendly nature of the original work. However, you can try searching on some fanfiction platforms and look for well - written non - inappropriate stories about their relationships.
Swimming is also a big theme. Given that they are all swimmers, many stories will involve them training, competing, or having some kind of revelation related to their swimming careers. For instance, a story could be about how Rin's new training technique inspires Haru and Makoto to improve their own skills.
One common theme is friendship turned into love. Since they are likely friends in the original story, fanfiction often explores how that relationship deepens into romantic love.
I'm not sure if there is a specific 'haru x makoto sick fanfic' available. You could try searching on popular fanfic websites like Archive of Our Own or FanFiction.net.
A common theme is friendship - turned - love. They start as friends and gradually develop deeper romantic feelings. Another theme is mutual support. They help each other through tough times, like Haru being there for Ryuji when he has family issues or Ryuji giving Haru confidence in social situations.