Another theme is the past haunting the present. In many 'dark secrets novel', something that happened long ago, like a crime or a family scandal, resurfaces and affects the current situation. It's like in 'The Secret History' where the past actions of a group of students come back to haunt them in the present day. It creates a sense of mystery and dread as the characters try to deal with these resurfacing secrets.
The theme of identity is also common. Characters may have hidden identities or be hiding aspects of themselves. They might be leading double lives, and these hidden parts are often at the core of the dark secrets. For instance, in some novels, a character who seems normal on the outside is actually involved in illegal or immoral activities that are part of their hidden identity.
Betrayal is a common theme. Characters often betray each other's trust, which leads to the creation of dark secrets. For example, in a story, a friend might steal a valuable item from another and keep it a secret, causing a rift in their relationship.
Gossip is a common theme. In small towns, word spreads fast, and secrets often get twisted through gossip. For example, in many such novels, a character's past mistake might be exaggerated through the grapevine.
Well, a frequent theme is reputation. Families often keep secrets to protect their family name. For example, if there was a family member who was involved in something illegal in the past, they would keep it a secret. Also, there are secrets related to family talents or skills that are not shared with the outside world. For instance, a family might have a unique way of making handicrafts that they don't want others to copy. Another theme could be family feuds that are hidden from the public eye, which can be very complex and involve many family members over a long period of time.
Cultural differences and secrets related to them. The Amish have a very distinct culture from the outside world. There might be secrets about how they maintain their traditions, or what they really think about modern ways that they seem to shun. For instance, some novels might explore if there are secret desires among the Amish youth to experience modern technology. This theme also ties into the idea of forbidden knowledge within the community.
Another idea is that Naruto has a dark secret regarding his past training. Maybe he had to do some unethical or dangerous things during his training with Jiraiya that he's ashamed of. This could include using forbidden jutsu or making deals with dark entities in order to gain power, which would be a huge shock to his friends and the village if it ever came out.
One common theme is hidden identities. Many fanfictions play with the idea that a character has a secret identity or a past that they themselves are unaware of. Another theme is secret prophecies. These are often used to drive the plot forward, as the characters try to figure out what the prophecy means and how to prevent or fulfill it.
Love is a common theme. In these fanfictions, the secrets often revolve around the characters' love for each other. For example, a character may keep a secret to protect their loved one.
Often, themes like trust, betrayal, and the power of keeping or revealing secrets are common in such cartoons.
Isolation is also a key theme. The 'dark stranger' is usually isolated from society either by choice or because of their nature. For example, in 'The Strange Case of Dr. Jekyll and Mr. Hyde', Mr. Hyde is an outcast. He exists on the fringes of society due to his dark and immoral actions. This isolation can lead to a sense of otherness and further fuel the dark nature of the character.