This drama is about two families, one poor, the other rich and how they become entangled in each others lives. At 52, one hour episodes, its a long haul but you get to know each character better which is always a good thing.
The two lead actors Hye-Sun Shin (who plays the sister Seo Ji-an) and Shi-hoo Park (who plays the brother Choi Do-kyeong) really do play their parts to perfection. But for me its the support cast who really knock it out of the park, especially Eun-Su Seo (who plays the other sister Seo Ji-soo) and Ho-jin Chun (who plays the father Seo Tae-soo), they are so good, they will no doubt get more dramas to work on as leads.
At 52 episodes you can expect a few slight appearance changes to the cast but Lee Tae-Hwan (who plays Ji-soo's boyfriend Seon Woo-hyeok) has ginger hair for 43 episodes then suddenly goes black and nobody wonders why.
The story lines are twisty but always interesting and every episode has a juicy cliff-hanger, so you can't wait for the next episode to start.
For me its the two mothers and the final episode that stop this being a 9. The mothers are just not good actors, they occasionally look at the camera, which is a no-no. And the last episode is rushed, to tie all the loose ends together. They should have split it into two seasons and gave all the characters a proper ending.
Even with those two little flaws, its still a must watch, but keep the hankies close, you will definitely get through a box or two.