I'm sorry, but I don't have specific recommendations for 'yuno and yuki lemon fanfiction' as it might involve inappropriate or non - mainstream content. However, you can try searching on fanfiction - dedicated websites and look for positive reviews to find good stories related to Yuno and Yuki in a more general and appropriate context.
There are many platforms where you can search for fanfiction about Yuno and Yuki. But instead of specifically lemon - themed (which often implies inappropriate content), you could look for adventure or friendship - based fanfictions. For example, Archive of Our Own (AO3) has a wide range of fan - created works. You can search for works tagged with Yuno and Yuki and then filter by the type of relationship or genre you prefer, like 'platonic' or 'action - adventure'.
Rather than seeking lemon fanfiction which may not be suitable, consider exploring the official source materials of Yuno and Yuki first. This will give you a better understanding of their characters. Then, if you still want fanfiction, look for ones that focus on character development, world - building, or unique plotlines. Some fanfiction communities on Reddit might be a good place to start, but be sure to abide by their rules and avoid any inappropriate content.