I watched this without having any expectations since I did not know the main leads. BUT I ended up loving it. I could not stop until I finished the entire series. I gave the storyline 9.5 because there were some parts where I wished they go more in-depth, especially about the parents of both main leads and Sara, and I would have loved to know more about the rest of the spies. I gave the music 9.0 because there was no particular music that really stood out to me. But overall, it was really good! The main leads' actings were on point! I really love the dynamics between the mains and the second leads! The second leads were also really cute and I love the development of their relationship as well. I definitely recommend it!

PS: I don't know if it is just me but the female lead reminds me of Ma Si Chun (the female lead from Chinese Drama Love Me If You Dare) and the male lead reminds me of Vin Zhang (from Chinese Dramas The King's Woman and I Will Never Let You Go). I will definitely be checking out more drama from both of them.