Cinderella with Four Knights

Cinderella

• Park So-dam as Eun Ha-won^[2]

A smart, athletic high school student. Ever since her mother died, she lives a terrible home life because of the ill-treatment from her new stepmother and stepsister. In order to pay for her college tuition, she accepts an invitation to the Sky House and gets entangled with the Kang cousins. She met Kang Ji-woon at their mother's funerals, giving him her white ribbon hair pin and he gave her his white arm band. Their friendship was a brief one, so they couldn't recognize each other when reunited after 10 years.

The Four Knights

• Jung Il-woo as Kang Ji-woon^[3]

The middle cousin, who went from an orphan living in poverty to a royalty overnight. Although he seems to be wild and rebellious on the outside, he is soft hearted, extremely lonely and sensitive on the inside. At first, he tries to get closer to Ha-won in order to protect Hye-ji, who likes Hyun-min. However, as he gets to know Ha-won, he gradually falls in love with her. He originally met Ha-won at his mother's double funeral with Ha-won's mother, and gave words of comfort and his white arm band to her, while she gave him her white ribbon hair pin. It is suggested that their friendship was a brief one as they could not recognize each other when they were reunited after 10 years.

• Ahn Jae-hyun as Kang Hyun-min^[4]

The eldest cousin, an arrogant playboy and smooth-talker who's used to getting whatever he wants in life. He firmly believes he can win any woman. At first, he appears to take an interest in Ha-won and pretend to be Ha-won's fiance. However, he is still in love with Hye-ji, his childhood friend and his dead best friend's sister, but he hide the fact and chose to push her away due to a childhood trauma. As the time comes he realises his foolishness for pushing Hye-ji away and apologises for what he did and go back to his first true love. He has a troubled relationship with his mother due her constantly pushing him to be Haneul Group's successor, and for abandoning him when he was younger, only coming back to ask about his position.

• Lee Jung-shin as Kang Seo-woo^[7]

The youngest cousin, a popular singer-songwriter and top star. He is a sweet, playful guy who is affectionate towards Ha-won whom he starts developing feelings for. He gives up his first love as he gets to know about Ha-won and Ji-woon's relationship. In the finale, it is hinted that he possibly ended up with Ja Young.

• Choi Min as Lee Yoon-sung

The secretary of Chairman Kang, and bodyguard to the three Kang cousins and Ha-won. He treats Ha-won really well and helps her settle into her new environment at Sky House. He protects Haneul Group by voting against the removal of chairman Kang, going against his mother's wishes. His mother is revealed to be Ji Hwa-ja, Chairman Kang's fifth wife.

People Around the Four Knights

• Son Na-eun as Park Hye-ji

A university student majoring in fashion design. She is a childhood friend of Hyun-min, and has liked him since they were kids. She tried using Ji-woon's crush on her to get closer to Hyun-min. She has a genuine and pure heart, but is constantly at battle with it because of Hyun-min constantly pushing her away. Especially after her brother's death.

• Kim Yong-gun as Chairman Kang Jong-du

Chairman of Kang Group and the Kang cousins' grandfather. He was reason behind Ji-woon not having his father present in his life, because he forcibly ended their relationship, and citing that people from different social classes should not be together. He almost does the same to Ji-woon and Ha-won, but relents and lets the couple be happy, not wanting history to repeat itself.

• Kim Hye-ri as Ji Hwa-ja

Chairman Kang's fifth wife, and the mother of Yoon-sung. She schemed to take over Haneul Group, by taking advantage of Chairman Kang being in coma, and put her son briefly as CEO of Haneul Group. Her efforts were foiled by Kang Hyun-min convincing 52% of the board against removing his grandfather, and also secretly by her own son. Chairman Kang divorces her, but relents and possibly remarries her again.

People Around Cinderella

• Seo Hyun-chul as Eun Gi-sang

Ha-won's father. He works as dump-truck driver at construction site. He originally believed Eun Ha-won to not be his daughter, and thus hated not only her, but her deceased mother as well, thus kicking her out. His theory was put down by Kang Young-jin, and he tries to make amends with his daughter again. He also moves his second wife and step-daughter to the same small room that Eun Ha-won slept in at the beginning of the series, as punishment for their cruel treatment of his daughter

• Choi Eun-kyung as Park Soo-kyung

Ha-won's stepmother. She works at a spa and dreams of getting her daughter rich and famous. She is eventually fired from her job for trying to offer her service as a spy to Madam Kang, in a vain and ill-thought out plan to have her daughter marry one of the Kang cousins and make her famous.

• Ko Bo-gyeol as Choi Yoo-na

Ha-won's stepsister. She aims to be a top star one day and marry Kang Hyun-min. Her grades in school were poor, seeing as how she couldn't get into University, and is lazy and unemployed. She tries to switch her advances to Kang Seo-woo, but is rebuffed by him, by writing in her autograph book to "be nice to Eun Ha-won". She's childish and immature because her mother constantly spoils her and never made her lift a finger to work in her life, and thus having to rely on her mother for everything.

• Cho Hye-jung as Hong Ja-young

Ha-won's best friend who works part-time at the cafe. She met Eun Ha-won when she couldn't afford food, and Ha won gave her some of her almost expired food, they have been best friends since then She has a mother who works full time, and a father who can't work yet due to recovering from cancer treatment. She is a fan of Kang Seo-woo, and possibly becomes his girlfriend in the series finale.