One common theme is the 'opposites attract' concept. Given sakusa's quiet and clean - freak nature and atsumu's more energetic and sometimes messy personality, this contrast often forms the basis of their relationship in fanfictions. Another theme is their mutual growth. They help each other become better players and people in many stories.
The contrast between their personalities. Ushijima is calm and collected, while Hinata is energetic and impulsive. This creates a dynamic that can lead to really engaging storylines in fanfics.
A popular trope in these fanfictions is 'Unspoken Understanding'. Ushijima and Shirabu seem to have an unspoken connection on the court, and fanfictions often explore this further. For example, with just a look, they can anticipate each other's moves. Another trope is 'Jealousy'. There could be a situation where Shirabu is jealous of the attention Ushijima gets, or vice versa, which adds an interesting layer to their relationship. And then there's the 'Secret Admirer' trope, where one secretly admires the other's skills or qualities, which can lead to a cute and sometimes slow - burn kind of relationship development.
One common theme is rivalry. Given their positions as volleyball players, many fanfictions explore how their on - court rivalry can translate into a different kind of relationship off the court.
One popular type might be the ones that focus on their rivalry turning into friendship and then something more. For example, there could be a fanfiction where they start off competing for a spot on the team but gradually realize they have a deeper connection. Another could be set in an AU (alternate universe) where they meet in a completely different context like at a music concert and their relationship blossoms from there.
There's a fanfic called 'The Bond Beyond the Net' which is really good. In this story, Ushijima and Hinata find themselves in a training camp together. Their different playing styles clash at first but then they start to learn from each other, leading to a deep friendship and more. It shows how their characters complement each other in unexpected ways.
There are many out there. 'Opposites Attract' is a really nice one. It delves deep into how sakusa's reserved nature and atsumu's more outgoing and flamboyant personality play off each other. The fanfiction does a great job of creating situations where they have to rely on each other, leading to a beautiful relationship development.
One popular ushijima x oikawa fanfiction is 'Parallel Lines'. It beautifully explores their relationship in an alternate universe where they meet under different circumstances and gradually develop a deep connection.
Some Tumblr blogs also post or recommend Haikyuu fanfictions. You can search for Haikyuu fanfic blogs and then specifically look for Sakusa x Atsumu stories on those blogs. The bloggers often give a little summary or their thoughts on the fics, which can be helpful in deciding if it's something you'd like to read.
" The Second Season of Ushijima-kun Okini " was a Japanese drama based on the manga of the same name by Manabe Shohei. The drama told the story of how the president of CowCowFinance, Ushijima Kaoru, and his assistants collected debts in a decadent and materialistic era. The plot of the second season continued to revolve around Ushijima and his team. They faced all kinds of people who tried to squander money but were unwilling to pay their debts. They used various means to collect debts. In addition, Ushijima Kaoru also had a classmate who was an intelligence expert, Suyosuke. Together, they revealed all kinds of secret information in society. The second season consisted of nine episodes and was released in 2014.