One characteristic is the exploration of their contrasting personalities. Akashi is often portrayed as strong, confident and a natural leader, while Kuroko is more introverted and underestimated. Fanfics usually play with how these two personalities interact and complement each other.
I'm not entirely sure what specific 'akashi x kuroko lemon fanfic' you are referring to. But generally, in such fanfics, it might explore a unique relationship between Akashi and Kuroko. Maybe it delves into their character development within the context of a different scenario than the original story.
The vampire theme itself adds an element of mystery and allure. Vampires are often associated with immortality, power, and a certain kind of dark elegance. When applied to Akashi and Kuroko, it gives the characters new dimensions. We can see them in a different light, dealing with vampiric instincts like bloodlust while still maintaining their core personalities. It also allows for new and exciting plotlines, such as battles between vampire clans or the search for a cure to vampirism if they choose to go that route.
A possible plot for a Female Kuroko x Akashi fanfiction could be set in an alternate universe where there are no gender - based restrictions in basketball teams. Female Kuroko joins Rakuzan instead of Seirin. Akashi, as the captain, is initially skeptical but soon realizes her potential. They start training together intensively. As they do so, they begin to develop feelings for each other. However, they face opposition from some of the team members who are not used to the idea of their captain being involved with a female teammate. But through their strong bond and love for basketball, they overcome these obstacles and their relationship blossoms.
One great Akashi x Kuroko fanfiction is 'The Red and the Blue'. It beautifully delves into their relationship, showing how Akashi's dominant personality and Kuroko's calm nature complement each other. The author does an excellent job of portraying their emotions in a Yaoi context.
Love or at least a deep emotional connection could also be a theme. The 'x' in 'akashi x kuroko' often implies some sort of relationship, and in a fanfic, this could be developed into a love story. It could show how they come to understand and care for each other on a deeper level, with various obstacles and challenges along the way that they have to overcome.
One plot idea could be that Kuroko and Akashi have to team up for an unexpected street basketball tournament against a group of international players. They start off with a lot of friction due to their past rivalry but gradually learn to work together and discover new aspects of each other's playing styles.
One challenge is that they have very different personalities. Kuroko is quiet and unassuming, while Akashi is more dominant and confident. So, it's hard to find a believable way for them to connect at first.
Another one is 'In the Eyes of Akashi'. This fanfic focuses on Akashi's perspective of Kuroko. It shows his admiration and the special place Kuroko holds in his heart. The author does a great job of exploring Akashi's complex character in relation to Kuroko.
One aspect could be the exploration of Akashi's possessiveness in the relationship. It might show how his intense personality affects his interactions with Kuroko. For example, he could be overprotective, not wanting Kuroko to be too close to other characters.