No, it's probably not popular. A good Naruto fanfic usually has a title that is both appealing and in line with the values of the Naruto community. This title contains a derogatory word which would likely turn off many readers, so it's not likely to gain much popularity.
Since the title seems a bit unorthodox, it's hard to tell precisely. But if we assume it's a regular Naruto fanfic with Mikoto in it, it might explore aspects of Mikoto's character that were not fully explored in the original Naruto series. It could be about her backstory, her relationships with other characters, or her role in some new plotline within the Naruto world.
One idea could be that Mikoto discovers baby Naruto alone and decides to take him in and protect him, raising him alongside Sasuke. This could lead to a very different dynamic in the Uchiha clan and Naruto's growth.
No. Given the rather odd and unappealing name 'tsume slut', it's highly unlikely to be a popular Naruto fanfic. Most popular Naruto fanfics have more recognizable and positive - sounding titles.
A 'naruto mikoto lemon fanfic' often has a blend of the Naruto universe's elements with the relationship between Naruto and Mikoto. The fanfic may include the use of jutsus, ninja clans, and the overall world - building of Naruto. Regarding the 'lemon' part, it usually means there will be some level of romantic or sensual undertones, which could be used to develop the emotional connection between the two characters. However, different authors will have different takes on how much and how they portray this aspect.
One idea could be a story about Kushina and Mikoto being friends when they were young and how their friendship influenced Naruto's life. For example, they could have made a pact to always look out for each other's children. Kushina might have told Mikoto some special Uzumaki techniques that Mikoto then passed on to Sasuke in a way. Another idea is a time - travel fanfic where Naruto goes back in time and meets his mother Kushina and Mikoto when they were in their prime. He could learn a lot about the past of the village and his family from them directly.
One main theme is often the relationship between different clans. Since Naruto is from the Uzumaki clan and Mikoto is from the Uchiha clan, the fanfic might explore how these two clans interact through their relationship. For example, in some fanfics, they try to bridge the gap between the two clans that have a history of mistrust.
Definitely not. The Naruto story has a well - defined family structure and character relationships. This fanfic concept goes against all of that. It's not only inappropriate but also disrespectful to the original story and its fans who expect the fanfics to be at least somewhat in line with the original world - building.
Perhaps a fanfic about a special training session. Kushina and Mikoto decide to train Naruto together. Kushina teaches him some unique Uzumaki jutsus, while Mikoto imparts some of the Uchiha's wisdom and combat skills. Through this training, Naruto not only becomes stronger but also forms a deep bond with the memories of his mother and Sasuke's family.
One possible plot could be that Mikoto somehow survived and she takes Naruto under her wing. She trains him secretly, using her Uchiha knowledge to make him stronger. This could lead to Naruto having a unique set of skills that no one else has.