I say this only through my opinions, I see that there are a lot of mixed reviews out there on this drama, but here I am giving my opinion on this drama and why I rated it high.

Story - 9.0/10 :
I recommend this drama, to the drama watchers who are looking for a light but historical drama. As for me, I was feeling like watching one and I noticed this drama started airing. I don't regret watching this drama as I actually thought this drama was fun to watch. Now let's talk about the plot. In the first 18 episodes, I do agree the plot is really missing a lot and it's definitely can't be considered as the best out there, but for a light drama, it's not the worst though, and maybe you could enjoy this drama as I did. As for the majority of the drama, comedy takes a big role through the drama, as for nearly every episode there would be time's where I couldn't stop laughing watching this drama. Near the end is where the majority of the story comes together and I've got to say the ending is very exciting. This drama throughout a lot of scenes that you wouldn't expect to happen and I was blown away by how well this drama did it. After every episode, I just couldn't wait to start the next. I'm very satisfied with the ending as I was happy to see that what they planned to do for Bianjing and the Imperial College was worth it. I expected that the whole drama would have no meaning at all and would just be fluffy the whole 30 episodes, but it didn't do that, in fact, the fluffiness stops not long after she graduates which gave a little sense of reality (I guess) as it made you feel like when you graduate, that is when you enter the real world and could face problems. This is why I rate the story a 9.5/10 since I didn't expect this drama to do this to me as a light drama, I think it did well.

Acting/Cast - 10/10 :
Zhao Lusi and Xu Kaicheng look like they were made for this role, the chemistry between the leads exceeded my expectation.
I've seen a lot of netizens commenting how Zhao Lusi's acting was quite annoying, but honestly, it didn't impact the way I watched it. I thought that Zhao Lusi's acting was quite cute overall and suited this drama and my expectations well. Although, (Zhao Lusi wears Korean makeup and her eyelashes and hair colour have annoyed many netizens since there are times where she looks like she is in a contemporary drama when she wears her own hair out it's been dyed brown which may affect the look of a historical drama) if you ignore this factor, then Zhao Lusi has done well in this drama. Zhao Lusi made Sang Qi feel lively and who was a smart girl.
This drama is my first Xu Kaicheng drama and I'd say his acting was well done in this drama. His acting skills were just what was needed for this drama. Xu Kaicheng is quite handsome and he's very tall and has more of a built body, which suited the role of the Deputy Chief of the Imperial College. I was really satisfied by the way he acted out his character throughout the story. The way he always acted around as Yan Yun Zhi to trick Zhou Wen Yuan, I got a tear out of my eyes at one point, and I'd say if he's able to make me cry, he is definitely a good actor.
Now about Ren Hao, to be honest, I hated his character (Zhou Wen Yuan) so much, Zhou Wen Yuan annoyed me all the time especially when he got very possessive over Sang Qi. If I'm at the point where I hate him, I guess he must be a good actor right? I'd say his visuals are handsome for a second male lead, also for a rebel. His eyes really told you his emotions and his feelings throughout the plot and I was impressed with the way he expressed the emotions through his eyes.
The supporting cast was pretty well done, if I have to say who would be my favourite supporting character I would have to say Yan Yan as he brought laughter from the times in the Imperial College right through to the end. In every character, it was wonderful to see how they act the characters when they grow older and go into the adult world.

Music - 10/10 :
I really like Liu Yuning's songs and I was happy to know that he sang a song for this drama. Zhao Lusi's song was also a nice one too I've got to say her singing skills have slightly improved. I was surprised to know that Zhang Yue (actor of Song Jia Yin) sung the opening song, her voice is really nice as well. All the songs suited the emotions the drama needed and I really like the whole OST of the drama.

Rewatch Value - 10/10 :
For me, it's hard to get over dramas that I feel just finished too fast, I could probably watch this another time but really depends on your opinion on rewatching dramas.

Overall - 10/10:
This drama has exceeded my expectations of thinking it was only going to be fluffy, I was very happy to see that this drama wasn't just full of fluff but there were a lot of tricks being played near the end which fulfilled just what I needed in a drama. To make this opinion I probably wouldn't have said this if I wrote this after watching the first 10 episodes. I think it's a good idea for you to watch the full drama to make an opinion on this drama because a lot changes after episode 18. So please do watch this drama and expect to see fluffy drama in the first 18 or so episodes but the story does not stop there when things change it gets very interesting and it is very intriguing to watch to the end. :)