Mikasa and Eren don't kiss in the manga. The focus of their connection lies in different aspects of their shared experiences and the evolving plot rather than a romantic kiss.
Sure, Mikasa kisses Eren. This occurs during a crucial and emotional part of the story that has a big impact on their relationship and the plot as a whole.
Character development is key. It should show how their relationship has evolved over time to reach that kiss moment. For instance, if it's set in the original 'Attack on Titan' universe, it should account for all the hardships they've been through together.
A good fanfiction would have well - developed characters. It should show how Armin and Mikasa's personalities lead to that kiss. For example, Armin's intelligence and Mikasa's protectiveness might play a role in their relationship development.
For Eren, he could start off as a bit of a rebel in high school. Maybe he's always getting into trouble for questioning the school's rules. But as he spends more time with Mikasa, he starts to see the importance of following some rules and also becomes more empathetic. Mikasa, on the other hand, can be developed as the quiet, studious type who slowly comes out of her shell because of Eren's influence.
One plot idea could be Eren and Mikasa being in a high school drama club together. They get cast as the lead couple in a play, which makes their real - life feelings for each other start to surface. As they rehearse, they face challenges like jealousy from other classmates who also have a crush on them.