I don't have enough information to determine if it's popular or not. It could be a niche visual novel that has a dedicated following, or it could be relatively unknown.
One popular theme is the exploration of the characters' relationships in different settings. For example, how the main characters interact in a modern high - school AU (alternate universe). Another theme could be the development of the characters' personalities in fan - created scenarios. Some fanfictions also focus on the comical situations that the characters from Himegoto can get into, like misunderstandings that lead to hilarious events.
I'm not sure specifically as I haven't played this visual novel. It could potentially be about a story of struggle, growth, or a unique fictional world with its own set of characters and plotlines.
You can start by looking on fanfiction websites like Archive of Our Own (AO3). It has a large collection of fan - created works, including Himegoto fanfiction. Another option is FanFiction.net. There are also some smaller, more niche fanfiction communities dedicated to anime and manga that might have Himegoto fanfiction. Just search for the title on these platforms and you should be able to find some good reads.
Another theme might be identity. Since she is a vampiress, she may struggle with her identity in a world that may not fully accept her. There could also be themes of love and loyalty, especially if she forms relationships with other characters in the story. In addition, the setting of the story, perhaps a modern or fantasy world, may bring up themes related to the clash or co - existence of different species or groups.
There is also 'A Certain Magical Index'. Although not strictly about vampires, it has a rich world of magic and different species. It has a complex plot and a lot of character development, much like what you might expect from a light novel in the vein of 'Seifuku no Vampiress Lord'. The world - building and the way different powers interact can be quite engaging.
Attacking dogs cartoons usually have dogs that look really fierce, with bulging eyes and raised hackles. The colors might be bold and the scenes could be full of action and chaos to emphasize the attack.