I'm not sure if it's popular. There are so many Naruto fanfics out there, and it's hard to tell which ones are really popular without doing some research. It could be that it has a small but dedicated following among fans who are interested in this particular scenario of Tsume being hypnotized by Naruto.
Well, if we exclude inappropriate content, a common theme could be the exploration of Naruto's mental state. Hypnotism in this context might be used to show his inner thoughts and fears. For example, it could be about how Naruto overcomes some hidden traumas through this hypnotic experience.
Another theme might be mystery. The hypnosis of the lemon could be part of a larger mystery. For example, who hypnotized the lemon and why? And what secrets are being hidden as a result of the hypnosis. There could also be a theme of power struggle. If the hypnosis gives someone control over the lemon, there could be a struggle for that power, either to maintain the hypnosis or to break free from it.
Well, it could be a really wild plot. Maybe Tsume is hypnotized by Naruto and starts to see things in a different way. It might involve some sort of adventure where Naruto's hypnotic influence leads Tsume to do things she normally wouldn't. However, this is all speculation as I haven't actually read the fanfic.
Most 'Naruto hypnotized lemon fanfiction' contains elements that are not suitable for a general audience. Instead, you could explore fanfiction where Naruto learns new jutsu or has adventures with his team. For example, there are many great fanfics that explore how Naruto might interact with other ninja villages in a diplomatic way while still maintaining his own values.
Kakashi could be a common character in these fanfictions. He's Naruto's teacher and mentor, so when Naruto is hypnotized, he would likely be one of the first to try and figure out what's going on and how to reverse it. Additionally, characters like Shikamaru, with his high intelligence, might be involved in devising plans to deal with the hypnotized Naruto.
Well, in a general sense, it might involve Issei using some sort of special power or situation to hypnotize Rias. The plot could then revolve around how this hypnotized state affects their relationship, perhaps leading to some unexpected interactions or adventures within the fanfiction's universe.
The main characters are clearly Rias and Issei. Rias is often a strong and important character in the series, and Issei is the one who hypnotizes her in this fanfiction.
Well, 'hypnotized lemon fanfiction' is not a very common type that I'm familiar with. Maybe you can start by looking for any fanfiction related to lemons (which could be a symbol or character named lemon) and then see if there are any with a hypnotized theme among them. It might take some time to dig through different fanfiction categories.
One interesting 'naruto hypnotized fanfiction' story could be about Naruto being hypnotized to forget his ninja skills and having to relearn them in a unique way. Maybe a villain uses a new type of jutsu to hypnotize him, and his friends have to figure out how to break the spell.