I'm not usually the type to write a review, but this one left a beautiful impression. It is worth watching till the end, but honestly, at first, I had my doubts since I'm not a fan of Korean Musical drama. However, the GCI and effects (whatever that's called) are beautifully portrayed. Sometimes the blue butterfly looks animated too much but is still brilliant. It's so Visually-pleasing.
When it comes to the story, It is excellent. I love the building of tension and conflict towards ep 4-6. Although it's short series, It is beautifully well written. I got inspired in the end and was on the verge of tears, binge worth.