This drama really is on the cutting edge for examining the social, emotional and physical relationships that exists between two adults. That relationship is expanded by the interaction with friends, co-workers and even parents. It also is realistic because in most long term relationships there are interventing circumstances that will change the "love story" of the adults involved. This drama has a good depiction of murphy's law. Everything possible started to go wrong because of one intervening party's opinion. I call in "enlightenment" combined with lust (initially).

The lust becomes respect and love and the enlightenment becomes the basis of collapse of this couple's plans.
The drama is extremely addictive with a maturer theme and filming - the story was well written and the actors were excellent throughout. Total investment in their outcomes. A good analysis of the uncertainties of what would or could be considered a certainty. A good analysis of obsession and its eventual outcomes. Without writing a spoiler - the ending was perfect - more of a reality (especially after understanding WeiWei's character).
I am really glad that I never watch the prologue "clips" and always fast forward to the story because it was apparently depicted in the finale. (don't like to know parts of the ending in advance).

The music was so good and set the tone for most scene changes or encounters. This drama is not for everyone and I would give parental guiding warnings if you have young viewers interested in checking it out.
Infidelity or cheating issues are not adulterous issues. All characters are single and dating.