I'm not sure specifically about Tobirama and Sakura lemon fanfiction. Fanfiction can vary greatly in quality. You could try searching on fanfiction - specific websites like Archive of Our Own. They have a wide range of fan - made stories, but be aware that lemon or adult - themed content might not be allowed on all platforms.
I'm sorry, but I can't recommend specific lemon (which often implies adult - themed content) fanfiction. However, you can try looking on fanfiction - dedicated platforms like Archive of Our Own and use their search filters to find Tobirama and Sakura - related fanfics that are more appropriate in nature.
One popular Tobirama and Sakura fanfiction is 'A Meeting of Eras'. In this story, Sakura somehow gets sent back in time and meets Tobirama. Their interactions are really interesting as they come from different times with different values and abilities. It shows how they gradually understand each other.
One possible plotline could be that Lemon is a new character who has some special power or knowledge. Hashirama and Tobirama, being the powerful shinobi they are, might be intrigued by this. Sakura, with her own skills, could form an alliance with Lemon. Maybe they all have to work together to face a new threat in the Naruto universe.
I'm not entirely sure about the common themes in Tobirama x Sakura lemon fanfics as I haven't studied them in depth. But generally in fanfics, there could be themes of unexpected relationships, character growth, and perhaps some exploration of their unique abilities within the Naruto universe in a more romantic or 'lemon - ish' context.
Power and leadership is also a theme. Tobirama was a powerful and important figure in the ninja world's history. Fanfictions may explore how Sakura, with her own set of skills, either challenges or complements Tobirama in terms of leadership and power - related matters. This could involve them working together to solve a major threat to the ninja world or dealing with internal village politics.
The theme of mutual respect also shows up a lot. Given their different backgrounds and abilities, they have to learn to respect each other. Sakura's modern medical knowledge and strong fighting skills can impress Tobirama, while Tobirama's wisdom and powerful jutsu can earn Sakura's respect. This mutual respect then forms the basis for their relationship in many fanfictions.
Finding a fanfic that combines Hashirama, Sakura, Tobirama and something named 'Lemon' might be a bit tricky. Hashirama and Tobirama are from Naruto, while Sakura is also from Naruto. 'Lemon' might be an OC (Original Character) or something specific to a certain subset of fanfics. You could start by looking at Naruto -centric fanfic communities and then narrow down your search based on those specific elements.
They could interact in a more intellectual way as well. Sakura, with her knowledge from the future, could introduce new concepts about medical ninjutsu and chakra theory to Tobirama. He, in turn, could share with her the secrets of some of the older jutsus that have been lost in her time. Their conversations would be a blend of mutual learning and challenging each other's ideas.
In fanfiction, Tobirama and Sakura can be an interesting pairing because of the skills they each possess. Tobirama was a powerful shinobi with unique jutsu, and Sakura has her own set of impressive medical and combat abilities. Their coming together could lead to some exciting adventures and storylines. Also, the age gap between them (although a bit odd) can be explored in different ways, like a mentorship - turned - romance kind of story which is quite engaging in the fanfiction world.