It may seem like it's not a popular k-drama, but for me, it really deserves to be popular. The k-drama is +15 but I honestly didn't see anything like kissing scenes, drugs, suicide... etc. I would really recommend it even to my friends. There was also a scene with Yeonjun from TXT. I saw that he appeared on a k-drama a long time ago but I didn't know it was on that k-drama so I was shocked and excited. At the beginning of the k-drama, it may seem like the story is talking about a cold teenager's life and stuff like that but in the next episode, everything (that you probably didn't expect) is explained like why was she cold, why a lot of people hated her, why does she feel bothered when she thinks about a birthday party... and many more. In a nutshell, it really really really deserves more popularity :)