It's hard to say it's a widely popular genre. 'Monster Musume' itself has a dedicated fanbase. But when it comes to 'harem' and 'lemon' elements in fanfic, these can be polarizing. Some people might be attracted to the idea of a harem in the Monster Musume setting, but the 'lemon' part can be off - putting to many. So overall, it may not be as popular as more general Monster Musume fanfic.
One common theme could be the exploration of different monster species' cultures. Even within the context of a harem and with the 'lemon' elements, there might be an underlying exploration of how different monster characters interact based on their species' norms. Another could be the power dynamics, as some monsters in Monster Musume have different levels of power or abilities, and this could play into the relationships in the fanfic.
Well, it is popular to some extent. In the 'Monster Musume' series, Kurusu's character has the potential for many different relationship dynamics, especially in a harem - like scenario. Fans are intrigued by the different personalities and traits of the monster girls and how they interact with Kurusu. This makes it a favored genre for those who like to explore different relationship - based storylines in fanfic.
A possible plot is that the main character discovers a hidden power within himself that attracts all the monster girls. As the harem forms, they have to deal with the outside world's reactions. The 'double' part could mean there are two main groups of monster girls, perhaps from different regions or species. Regarding the 'lemon' element, it could be about the characters exploring their new - found feelings through soft and passionate embraces. For instance, a cat - girl might purr contentedly when hugged by the main character, leading to a deeper emotional connection.
When writing, focus on the emotions of the characters. Kurusu might be feeling a mix of excitement and nervousness. The pregnant monster girls could be experiencing hormonal changes specific to their species, which might lead to different emotional outbursts. Use descriptive language to bring out these emotions. For instance, 'Kurusu's heart raced as he looked at the ultrasound of his harpy girlfriend's egg - like pregnancy.'
One common theme is acceptance. Kurusu has to accept the monster girls for who they are, and they also have to accept him. Another theme is love and relationships. Since it's a harem concept, there are multiple romantic interests. Also, cultural differences between humans and the different monster species can be a theme, as they learn to co - exist and understand each other.
The fanfics usually involve a lot of character - centered stories. For example, an individual monster girl might have a backstory about how she came to be in the harem or her past experiences that shaped her personality. This helps to make the characters more three - dimensional and the overall story more engaging.
One common theme is friendship. Papi's character often forms strong friendships with other characters in the fanfic. Another theme could be adventure, where Papi goes on exciting journeys with her companions. And of course, there's often a touch of romance as well, exploring her relationships in a different light.
One interesting aspect could be the unique character interactions. In Monster Musume fanfics, the different monster girl species bring diverse personalities and cultural backgrounds, which can lead to really engaging and sometimes comical exchanges. For example, a lamia might have a different view on relationships compared to a harpy. Another aspect is the exploration of new storylines. Fanfic writers often take the basic premise of the Monster Musume world and create their own adventures, like the monster girls going on a quest together. It also allows for a deeper look into the emotions of the characters. Since the fanfics can focus more on individual character development, we can see how the monster girls and human characters deal with things like love, friendship, and acceptance in more detail.
Smith Lemon is surely a main character. Then, depending on the fanfic's focus, it could be a mermaid - like monster musume. She could bring a sense of mystery as she is from the underwater world. There might also be a centaur - type character who is strong and has a noble personality. All of these characters, along with Smith Lemon, would play important roles in the story, each with their own goals and personalities that collide and interact.