It could be a way to extend the popularity of the original novel. By creating an 'extra novel', the author can keep the readers engaged for a longer time.
The 'extra novel' may have a significance in terms of character development. It could show the growth or regression of characters outside the main storyline. This can give a more comprehensive view of the characters' personalities and motives, and in turn, make the whole fictional universe more believable and immersive. For instance, if a character seemed rather one - dimensional in the main novel, the 'extra novel' could add depth by showing their past experiences or internal struggles that were not explored before.
The significance might lie in filling in the gaps of the main story. Maybe there were some loose ends or unanswered questions in the original novel, and the 'extra novel' is there to tie them up neatly. It can also provide a different genre - like if the main novel was a mystery and the 'extra novel' has elements of romance within the same world.
The significance could be in differentiating a particular set of novels. It might signal to readers that these novels have something special or extra compared to other novels.
It could be a story that delves deeper into the concept of love equations. Maybe it shows different ways love can be expressed or calculated in a fictional or metaphorical sense.
I'm not sure specifically as I haven't read it in detail. It could be about a variety of things like an extra story related to a main novel, perhaps exploring side characters more deeply or expanding on events in the original novel in a different way.
The sex ed extra credit comic might focus on providing additional educational information related to sex in a visual and engaging way. It could be significant in enhancing understanding and breaking taboos.
I'm not sure specifically as there are countless fanfictions. It could be about exploring additional storylines that weren't in the original novel, like developing side characters more deeply or creating new relationships between characters.
I don't have enough information to determine if it's popular. It could be popular among fans of the original novel who are eager to get more content related to it.
[The following conclusion is that there are many types of novels and topics for extras, including urban novels, fast novels, and entertainment novels.] Some of the novels revolved around the protagonist's transformation from an ordinary person to an actor. Some of the novels even added fantasy or system elements. However, the current search results did not provide enough information to answer this question. Therefore, he needed to search for more information about the novel.
There were a few novels related to being an extra, including "I'm an extra in Hengdian,""I'm an extra in Escape Game,""I'm an extra in iPartment,""I'm an extra in Harry Potter,""I just want to be an extra,""I'm an extra in the world of fast travel,""Starting from an extra (Rebirth),""I'm an extra in Escape Game,""Entertainment: An extra, but was caught to challenge the Masked King," and so on. These novels covered different topics and plots, including urban emotions, suspense reasoning, time-travel, and so on. However, because the search results provided did not provide a specific summary or evaluation, more detailed information could not be provided.
Maybe it's a religious genre. Sundays are often associated with religious activities in many cultures. So, 'the extra good sunday story' could be about a spiritual awakening or some religious experience that happened on a Sunday.
Reading the extra novel can also enhance the reading experience by giving more context. There might be details about the world - building in the extra content that make the fictional world of the main novel more vivid and believable. For example, it could explain some cultural or historical aspects of the fictional world that were only briefly mentioned in the main story.