Friendship is a very common theme. These four characters are often depicted as having a strong bond, supporting each other through tough times.
Love and relationships also play a part sometimes. It might not be the central focus, but their interactions with male characters in the Naruto universe and how their friendships are affected by those relationships can be explored in fanfics. For instance, how Hinata's relationship with Naruto impacts her friendship with the other girls or how Sakura's feelings for Sasuke influence her interactions with Ino and Tenten.
Another theme could be overshadowing. Maybe they are constantly in the shadow of more powerful characters. For instance, Sakura might feel overshadowed by Naruto and Sasuke's power, leading to her feeling 'weak' in comparison. This can create a sense of inferiority and drive the plot as they try to find their own identity and strength.
Well, a lot of these fanfictions deal with power and control. Vampires are often associated with power, so when a character like Tenten becomes one, it's about how she uses or misuses that power. Also, themes of love and loyalty are common. Ino might have to choose between her loyalty to her friends and her new vampire instincts. It makes for some really intense and emotional storylines.
Sakura could develop from being a somewhat self - conscious girl always trying to impress Sasuke to a confident ninja in her own right. Hinata might grow out of her extreme shyness and become more assertive, especially in her interactions with Naruto. Ino could develop her mental abilities further and learn to use them in more creative ways. Tenten might expand her weaponry knowledge and even invent new types of weapons.
Maybe a fanfic set in a modern - day AU (alternate universe). Sakura could be a doctor, Hinata a yoga instructor, Ino a florist, and Tenten a martial arts teacher. Their lives intersect in a small town, and they form a sort of girl - power group that helps each other out in different situations, like dealing with difficult customers or personal relationship problems.
Maybe a fanfic about a training camp they attend. Sakura and Ino might have a friendly rivalry during the training, while Tenten and Hinata help each other improve. They could learn new techniques from each other and also have some fun girl - time in between the intense training sessions.
It could be a fanfic about a time - travel adventure. The four kunoichis are sent back in time for some unknown reason. They have to adapt to the past environment and use their skills to survive. Sakura has to deal with the lack of modern medical facilities, Ino has to figure out how to use her jutsu in a different era, Tenten discovers new and ancient weapons, and Hinata has to face different challenges with her Byakugan. They work together to find a way back to their own time.
Friendship is a very popular theme. These four characters have different personalities, and seeing how they become friends and support each other is really interesting. For example, Hinata's shyness and Sakura's boldness can create a great dynamic.
Since I'm not overly familiar with a specific 'sakura hinata ino lemon fanfic', but generally in fanfics about these characters, friendship themes are common. They are all from the Naruto universe and their relationships with each other, whether it's the bond between Sakura and Ino as former friends turned rivals and then friends again, or Hinata's shy yet strong - willed interactions with them could be explored.
A fanfiction could focus on a mission where they are the main characters. Sakura uses her medical ninjutsu and brute strength, Ino her mind - related jutsu, Tenten with her weaponry skills, and Hinata with her Gentle Fist technique. They encounter a powerful enemy, but through their cooperation and the fact that they are all strong in their own ways, they manage to overcome it.
One popular hinata sakura ino tenten fanfic could be 'The Bond of Konoha Girls'. It focuses on their friendship and how they support each other during various missions in the Hidden Leaf Village.