In 'Your Lie in April', there's a sense of sharing the story of growth and love through music. Although not a direct quote about sharing stories, the overall theme of how the characters' lives and their emotional journeys are expressed through music can be seen as a form of story - sharing. Music becomes the medium through which they convey their experiences, much like how sharing stories can be a way to convey our own experiences.
Yes, there might be. The Naruto and Attack on Titan fandoms are both huge, and fans often like to cross over their favorite characters in fanfiction. So it's quite possible to find Eren - from Attack on Titan - in Naruto fanfiction. However, it may not be as common as fanfictions within each respective universe.
Fanfiction about Eren and Levi kissing can be quite interesting. It might explore a different side of their relationship. Some fanfictions in this regard could be about a moment of emotional intensity between them, where the kiss represents a deep connection that goes beyond their usual interactions in the original story.
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.