One reason could be copyright concerns. The Naruto creators own the rights to the story and characters, and fanfiction might be seen as an infringement without proper authorization.
Maybe a rogue ninja who has learned about modern technology and uses it to his advantage. He could be stealing valuable ninja artifacts and using modern gadgets to cover his tracks. He's smart like the villains in Case Closed, but also has the power of a ninja. He would be a difficult opponent for Naruto and Conan to face as he can blend the two different worlds' tactics.
One interesting 'cold case Naruto fanfiction' could be about an unsolved mystery from the Hidden Leaf Village's past. Maybe it involves a missing-nin who disappeared under strange circumstances long ago and new evidence comes to light. For example, a forgotten scroll is found that has clues about this ninja's real motives for leaving.
One reason could be for the sake of creating unique storylines. By making Naruto look like a girl, it can introduce new romantic interests or change the dynamics of his relationships. For example, it might lead to different interactions with Sasuke or other characters.
One idea could be that Naruto and the characters from Case Closed are in a world where they have to solve a mystery related to a powerful ninja artifact that has been stolen. The thieves are using some strange Case Closed - like detective techniques combined with ninja skills to cover their tracks.
One idea could be that Naruto and the Case Closed characters team up to solve a mystery in the Hidden Leaf Village. Maybe there's a string of strange disappearances that seem to have a connection to a powerful jutsu gone wrong.
To write a good 'cold case Naruto fanfiction', start with a strong hook. Maybe open with a discovery of a strange object that is related to the cold case. Then, develop the characters' detective - like qualities. Naruto could use his determination and Sasuke his intelligence. Build suspense throughout the story. Keep the readers guessing about what really happened in the past. Also, make sure the solution to the cold case is both surprising and logical within the context of the Naruto world.
" The Golden Case of the Great Tang Dynasty " was a novel written by the Dutch sinologist, Gulik van Gulik. The novel used Di Renjie, a famous minister of the Tang Dynasty, as the protagonist, telling the story of his legendary experience of being an official and helping the people to eliminate evil. There were a total of 24 stories in the book, and one of them was the Golden Case. This novel showed Di Renjie's integrity and intelligence through the detective plot, and also outlined the amorous feelings of the Tang Dynasty. The Golden Case of the Great Tang Dynasty was translated into many foreign languages and published, leaving an important mark in the history of cultural exchanges between China and the world.
" The Great Tang Di Gong Case: The Golden Case " was a novel written by the Dutch sinologist, Gulik. It described the legendary experience of Di Renjie, a famous minister of the Tang Dynasty, who was an official who dealt with cases and helped the people eliminate evil. There were a total of 24 stories in the book, and one of them was the Golden Case. In this case, Di Renjie discovered that his good friend Hou Yu was the murderer of the Gold Case. Hou Yu was Di Renjie's good friend and had a noble status, but he used the temple's Buddhist staff to smuggle gold and cast it into gold ware. This novel showed Di Renjie's wisdom and sense of justice through the detective plot, and also revealed the dark side of Tang Dynasty society. " The Great Tang Di Gong Case: The Golden Case " was a work that was well received by readers. Although it was not regarded as a world-famous work on a global scale, it had a certain status among detective and reasoning works.
We can draw the following conclusion: The gold case in the case of Di Gong of the Tang Dynasty is related to jade. Yu Su was a woman from Baekje who was kidnapped and used to find the whereabouts of gold. She devised a plan to frame others, but in the end, the information revealed that the gold was not actually a weapon, but real gold. However, there was no clear information about Yu Su's specific role and motive in the case, as well as whether she was the mastermind of the case. Therefore, we are unable to get a definite answer to the questions regarding the Golden Case and Yu Su in the case of Duke Di of Tang.