Di Renjie didn't have a niece. In the drama, Di Renjie deliberately fabricated the identity of a niece named Ruyan in order to lure the snake out of its hole. The Spirit Snake had sent Su Xian 'er to impersonate Di Renjie's niece, but Di Renjie had seen through her. However, because Su Xian 'er fell in love with Li Yuanfang and betrayed the Snake Spirit, Di Renjie officially adopted her as his niece and gave her the name Di Ruyan. Therefore, Di Ruyan became Di Renjie's real niece. In summary, Di Renjie did have a niece named Ruyan.
Yuan Fang in Detective Di Renjie really liked Ruyan. In the play, Yuan Fang was shocked and delighted when he first saw Ruyan. His love for Ruyan could also be seen in his behavior and expression. Although there were other female characters in the play, such as Xiaoqing and Wu Yuanmin, Yuan Fang's feelings for them were not as deep as for Ruyan. However, the search results did not provide clear information on whether Yuan Fang and Ruyan would eventually become husband and wife.
Di Ruyan didn't appear in Detective Di Renjie 3 because Qian Yanqiu had originally planned to ask Jiang Xinyan to continue playing the role of Ruyan when the third film started filming. However, Jiang Xinyan had changed careers to become a producer and couldn't participate in the film. Therefore, there were no actors like Yan in the third film. In the fourth movie, Qu Zha Zha took over the role of Ruyan. The director found an explanation for Ruyan's absence in the third film: Ruyan went home to take care of Di Renjie's brother, so she was not by Di Renjie's side in the third film.
Di Renjie was most touched by Ruyan's change and her sincerity towards him. Ruyan was originally a member of the Snake Spirit Organization and was sent to spy on Di Renjie. However, in the process of getting along with Di Renjie and Li Yuanfang, she was touched by their sincerity and decided to turn over a new leaf. Di Renjie gave Ruyan meticulous care, took her as his adopted daughter, and gave her the name Di Ruyan. These actions moved Ruyan very much. From then on, she found the feeling of home and understood why she loved and why she hated. Therefore, Di Renjie was most touched by Ruyan's change and her sincerity towards him.
Di Renjie's Ruyan was originally a bad person. She was originally a member of the Snake Spirit Organization and was sent to Di Renjie to spy and steal information. However, as time passed, her heart was gradually moved by Di Renjie and Li Yuanfang's sincerity. She eventually turned over a new leaf and was recognized as Di Renjie's niece. She helped Di Renjie solve the case in the play and was appreciated by Wu Zetian. Therefore, Ruyan in Di Renjie could be said to have changed from a bad person to a good person.
The following conclusion: In Detective Di Renjie 2, Li Yuanfang and Ruyan were a couple. They went to the Yue clan to investigate the case and finally solved the big case. Because of their achievements, Wu Zetian officially gave Ruyan the name Di Ruyan and made her Di Gong's right-hand man. There was no clear information about Li Yuanfang's ending.
There was a complicated relationship between Li Yuanfang and Ruyan in Detective Di Renjie. In the drama, Li Yuanfang had deep feelings for Ruyan, and Ruyan also had special feelings for Li Yuanfang. However, specific information about whether they became husband and wife or married was not clear. Therefore, it was impossible to determine whether their relationship would develop further.
Di Renjie set Li Yuanfang and Ruyan up. In Detective Di Renjie, Li Yuanfang and Di Ruyan had deep feelings for each other. In the play, they hugged after they separated. In addition, Li Yuan Fang and Ru Yan did get together in the end. In Detective Di Renjie: Doubtful Shadow of the Guan River, after Di Renjie returned to Luoyang, the red cloth that was only used for marriage was hung on the door beam of Di Mansion, as was the sedan chair that Ruyan rode in. Their relationship was supported by Di Renjie.
Di Renjie liked the female lead, Li Wanqing.
According to the search results, it was confirmed that Di Renjie liked Cao An. In the work, Di Renjie showed deep feelings for Cao An. The relationship between them had experienced many twists and turns and challenges, but in the end, they chose to protect each other at the moment of life and death. Di Renjie's wisdom and Cao An's silent support turned the situation around, showing their close relationship. Therefore, it could be said that Di Renjie liked Cao An.
In Detective Di Renjie II, the relationship between Li Yuanfang and Ruyan was established bit by bit. Their feelings for each other deepened over time and the accumulation of cases. In the drama, Ruyan had always been by Di Renjie's side and became his right-hand man. They had experienced many dangers and difficulties together, and Ruyan had protected and helped Di Renjie many times. Although there was no specific mention of whether they had become husband and wife, the feelings between them grew stronger and stronger, showing deep kinship and love.