Well, AO3 is the go - to place. It has a great search function that allows you to specifically look for Armin x Jean fanfiction from 'Attack on Titan'. You can also try Wattpad, although it has a more mixed bag of content. Sometimes, Tumblr might also have links or short fanfictions related to this pairing if you search through the relevant tags.
One great 'Attack on Titan Armin x Jean fanfiction' is 'Bonds Beyond the Walls'. It beautifully explores their relationship as they face the challenges of the Titan world together. The story delves deep into their mutual respect and how it evolves into a strong bond. Another is 'Dawn of a New Alliance' which shows them working side by side in a post - Titan - threat world, where their friendship takes on new dimensions.
Some fanfics might explore a romantic relationship between them in a more secretive or forbidden way. Given the military setting and the overarching plot of Attack on Titan, their relationship might be something they have to hide. This adds an element of tension and drama to the story, as they navigate their feelings while also dealing with the threats of the Titans and the politics within the walls.
One popular theme is the growth of their relationship. Starting from distrust or indifference and evolving into a deep friendship or something more. Another theme could be them facing challenges together, like a particularly difficult Titan attack where their combined skills are put to the test. Also, the theme of sacrifice might be present, where one is willing to sacrifice for the other in a life - or - death situation.
One popular trope is the 'enemies to lovers' dynamic. Given their positions as former enemies in the main story, it's common for fanfictions to explore how they transition from hostility to love. Another trope is the 'hurt/comfort' where, for example, Annie might be injured or in distress, and Armin is there to comfort her, which deepens their bond.
One popular theme is their friendship evolution. As they grow up in the dangerous world of Attack on Titan, their bond changes and deepens. Another theme could be sacrifice. How far would Eren or Armin go to protect each other? And there's also the theme of trust. Given the complex and often deadly situations they face, trust between them is crucial and can be a major focus in fanfiction.
You can try fanfiction websites like Archive of Our Own (AO3). There are a large number of Attack on Titan fanfics there, including ones about Jean and Armin. Just use the search function and type in 'Jean x Armin' within the Attack on Titan fandom section.
Another theme is growth. They both grow as characters throughout the series, and in fanfictions, this growth is sometimes shown in relation to their relationship. Maybe Armin becomes more confident and Mikasa learns to open up more because of their bond.
In the 'Attack on Titan' Marco x Jean fanfiction, their relationship is often complex. They are comrades in the harsh world within the story. Jean initially may seem a bit self - centered, but Marco has a positive influence on him. Their bond is one of mutual growth, as they face the terrors of Titans together and also deal with the politics and rivalries within the military.
Well, in many fanfics, a popular plot is when Eren and Armin have a disagreement about how to deal with the Titan threat. Eren might want to be more aggressive, while Armin advocates for a more cautious approach. This leads to a rift between them for a while. But as the story progresses, they realize they need each other and come back together stronger. Another plot could be them exploring a new area outside the walls and encountering new types of Titans or mysteries that they have to solve together.