All three sister are very different from each other which doesn't mean one is right or other is wrong
all have there pro and cons

Gong Min Jung role was what impressed me the most....
Jang Ma Ri
A shameless corrupt reporter which you can't prove corrupt because she believes in her own lies very honestly.
That story was my version of the truth, you have your own version of the truth and I have my Own,
Your truth was pitted again mine, and mine ended up winning today, I love that scene ( ep 11) when our Lead protagonist left speechless by a side character because, not always you win everywhere, some people will out match you, no matter what

Oh In Joo( Kim Go Eun )
she shows hidden desires of every Average working person, they all want to become rich and live a comfortable life but are not able to, when get opportunity most of them will act just like Oh In Joo did. but viewer wanted to call her greedy, are you one who will give up 2Million USD when you found it, NO if you say yes, your Lier.

Oh In Kyung ( Nam Ji Hyun )
she has her own principle and think they are above other but she is no better then anyone else when it come to her own family her younger sister she will abandoned her own principle and will do anything to protect what she love most just like all others, but she like to blame others for there selfishness while she give her self a privilege
she believe herself of something that is one and only pure journalist but she isn't , she is same as all others.

Oh In Hye
Most of people disliked her but i don't dislike her neither i like her fondly, she is there to make people see that not all rich are bad and all poor are victim which she said
that is just poor mentality to blame rich people for all there problems,
she was not great as sister, she doesn't care about those sister who she never choose, but she was loyal to her only friend she choose herself, she was rude to her sister but there was love even in her, which she was not able to show toward her sisters but was able to love her only friend,

i hated Oh In Kyung and Ha Jong Ho couple it was really wrong of them to make those two ending up together and leave
Oh In joo and choi do Il just at flirting, at least a kiss to conform there feelings toward each other

Choi Do Il ( Wi Ha Joon )
Good this man was so nice here and the unspoken chemistry between him and In Jo was amazing to watch
sub-- flirting between those two between that tens situation was a reliving wind
at airport i was waiting for them to KISS but no director did not have budget to include kissing scene.......