Being thirty doesn't mean you have figured out your whole life, or that your life is stable, your love life is perfect, it is about how chaotic life is even if your just turning 30.
This story is about the life of 3 women who is about to turn thirty. One finding true love, one in a toxic relationship and another finally letting go of her traumatic past.
I'm not yet thirty so I don't think I can judge this drama fairly in terms of depth and meaning. At times it's depressing to see the main lead trying to hold onto a relationship while fulling knowing its toxic and how she refuse to have a proper communication with her boyfriend who she suspect is cheating on her. And in the end her own immature approach to her own issues and her reluctance to face her problems resulted in her paying a high price with her career.
In the end this drama shows you how imperfect you are no matter how old you get.