I watched this drama because of Seo Woo since then I have watched her in Cinderella's sister and The Housemaid and I have become curious of her dramas as a main lead character so I watched this! For the first until the fifth episodes hooked me a lot however it is too detail to narrate the childhood life of Kang Yi Kyung and Kang Seo Yeon. I have skipped a lot of episodes because it is filled with fillers about toxic people like Seo Yeon, a habitual liar and the step mother Shim Hae Soon who is a manipulative bitch and annoys me a lot that sometimes these two were the reasons I want to drop this drama. Kang Seo Yeon's character development is very low that she have changed her attitude nearing to the end of the story because she wants to have her liver donated by Kang Yi Kyung... like what the f*** she doesn't deserved it! I feel really sorry about the people whom Seo Yeon hurt the most - Yi Kyung... I wonder why Seo Yeon didn't go to jail but she should have gone to jail after all what she did to Yi Kyung, Ha Jun and Ha Jun's mother! She should have been punished to jail or she have died at least in the end. I really hated the plot twist that Seo Yeon is the twin sister of Yi Kyung... it's like Min Seol Ah and Seok Kyung in Penthouse..

My favorite scene is that the stepmother of Kang Yi Kyung have known that her former husband was killed by Kang In Chul... and finds out that Shin Gi Tae was framed and was felt unjust because of In Chul to get what he wants in order to achieve his selfish position as a police.. So far, In Chul have took care his victims but in the end it was really all his fault! Then Shim Hae Soon felt sorry to Kang Yi Kyung for what she have done to her for many years and felt guilty towards her!

So far I love the casts despite they're underrated but they surpassed my standards of their acting skills!
I have seen how Seo Woo improved her acting skills compared to her drama Cinderella's sister.. Seo Woo made me cry and brought me joy watching in this drama! I hope she comes back in drama

It's my first time to encounter Kim Yoon Seo in a drama that she really made me annoyed her rolling eyes and her toxicity. She deserves to play a good main lead role and she's a good actress really!

Park Jin woo is my first time to see in this drama also! I have seen how natural his beauty is and I love his acting skills that I really want to look forward for his dramas but he is so underrated and he deserves such recognition!

Lee Ji Hoon is also my first time to see in this drama and he reminds me of Kim Seung Dae in That Sun in the Sky! I love how he act as an antihero in this drama and how protective he was for Kang Yi Kyung!

So far bittersweet hate and love for this drama that gives me depression and makes me cry because of these characters but I really love the story... I hope TvN would create more daily drama as good as this! I love how powerful the use of element of revenge in this drama... it's really rare to see a daily drama with addictive revenge stories like this!

Glass Mask would have been better if the narration during the child hood of Yi Kyung and Seo Yeon would have appeared in the flashbacks instead of appearing in the first episodes and also they should have shorten it with only 20 episodes when most of the episodes are 75% fillers and unnecessary