Too bad I have watched Crash Landing on You (CLOY) ahead of this one, hence knocking 1 star off as Son Ye-Jin really amplify her acting skills on CLOY. Watch if you're new to Son Ye-Jin and Jung Hae-In, and suddenly become fans of them. Ye-Jin brought up her strong sincere expression acting in here as usual
The story depicts of a noona (elder sister) who fell on love onto her friend younger brother. This drama explore strongly on Korean/Asian culture on taboo of dating an older person, from lower social standing as a stigma (sorry this is generic bias/perception, does not mean to degrade any Korean/Asian reader). You will be brought through the joy of love (anyone needing ideas on dating can watch here :), the pain / anger due to parents rejection (actually this k-drama only Yejin's mom rejects this strongly), how a filial daughter suffers through the ordeal as she fight against harassment in office and rejection at home on same time.
In summary, this k-drama is for you if you can spend the time to appreciate the romance, the anger/frustration. In fact I took it slow at the beginning and binge watching at the last 3 episodes.
BTW, watching this allows us to appreciate rain more, as miracle tend to happen on this time :). Happy watching