I did not expect this drama to become one of my favorites. I started it without really knowing what it's about and thought it'd just be one of those cliché romance dramas, but it was so much better. The concept of having those "cells" convey what happens in your head in different situations is so smart, it's kind of like "Inside Out" the movie, but executed so much better and funnier, there were also so many more feelings and situations discussed, and all the cells are hilarious and relatable . A lot of people have a problem with the characters/ conflict in the relationship, but I think it's very realistic, although the characters make you mad for not expressing their feelings better and for causing misunderstandings. Anyhow, I enjoyed this drama so much. The romance is so cute and the cast is well chosen, and the acting is very good! I'm looking forward to the second season of this. The director is so smart and I hope the drama won't be ruined with the upcoming season.