Right from the start, we know who Miao Miao (喵喵) was because of her nickname and the article she wrote. Then it was subtly hinted that Zi Hong was Qing Ting (蜻蜓), which was confirmed through various scenes and flashbacks.
It wasn’t until episode 5 that it was revealed that Dong Han was Xi Shuai (蟋蟀). The other characters did not know of his identity, not yet. Miao Miao and Zi Hong knew that he was back, because of the wooden tags he’d created and placed on the trees to inform them that he still remembered them. However, they did not know who he was as of recent. He knew who Miao Miao was right from the start, because of the article. Then later knew about Zi Hong, because of the sealed documents they managed to retrieve. Zi Yan had suspected him of something or at least saying how he seemed so interested in Zi Hong’s situation yet he avoided the question totally. Of course, she wouldn’t be able to guess their link due to the lack of information but knew something was up. So the final question is: Who is Xiao Cao (小草)?
It was revealed in episode 2 that Jia Yuan couldn’t possibly be Xiao Cao, because she was Zi Hong’s cousin, which explained why Xuan Xuan looked like Zi Hong when Zi Hong was younger. It was just that she didn’t know about it. He secretly tried to help her out from time to time. It wasn’t until the last episode (Episode 10) that she knew he was the secret person who helped her and Xuan Xuan survived all those times with the money and secret card. Yet she still didn’t know their connection as cousins yet. But it sure ruled her out as being Xiao Cao early on.
So between Zi Yan and Yong Mei, who is Xiao Cao? The Wiki page for the drama had changed on and off with Zi Yan being Xiao Cao or not. It seemed obvious from the plot thus far, wanting to pair the four key characters of twenty years ago together. However, it hasn’t been revealed yet in the drama so I think it’s fair to discuss. (And because Wiki’s unreliable in many ways.)
During that one conversation, it seemed like Zi Yan was Xiao Cao because although she mentioned her father, it could be the same as the other two–and how she got adopted as well. The majority of her background was kept a secret, except for her little talk with Dong Han. (Yes, others were kept in private too but it was eventually revealed.) Then there was also the part where Dong Han and Zi Yan tried to comfort Yong Mei regarding the newspaper matter. It seemed like Dong Han wasn’t the only one happy when discussing the articles, especially how we knew why he had to defend Miao Miao’s work. Yet Zi Yan was also complimenting the works. Although that could mean anything, still a little clue. Up until now, one could guess but we can’t be too sure if the writers decided to go toward a different path. In a way, it’s cute if Xi Shuai and Xiao Cao ended up together. However, it would also end up being a cliche because Miao Miao and Zi Hong were already tied together.
The reason why I want to include Yong Mei is because anything is possible. Even if we know early on that she’s the daughter of the head commissioner, it still could change. Her files could be sealed like the others. She could be adopted by the Luo after the accident. She might not remember what happened after the events or was still traumatized by it hence forgetting. It could happen, especially after losing her parents, she lost her friends too because they were all separated. Then it would also explain why Dong Han could possibly fall for her later like some of the trailers indicated. I would hate to think that Dong Han would betray Zi Yan because somehow Yong Mei finally got to him. Or the whole opposite attracts or whatever else. If she was Xiao Cao, he could relate to their childhood together and feel the need to reconnect with her. Then it would explain their conversation in one of the trailers regarding how he said he only wanted her to be safe.
*All images were captured by DTLCT.