Main •
Ji Hyun-woo as Lee Young-guk :41 years old, a widower, still grieving over the loss of his wife two years previously, with whom he had three children. He is the corporate chairman of FT Group (including Fantom) and is an attractive man in his early forties. In a twist of fate, Young-guk met Dan-dan when he was in military service. •
Lee Se-hee as Park Dan-dan •
Kim Min-seo as young Park Dan-dan :27 years old, bright and bold personality, a live-in tutor of Lee Young-guk's children, a confident 'handmaiden' who seeks her own happiness. Dan-dan first met Young-guk when she was 12 years old. •
Kang Eun-tak as Cha Gun :The youngest son of Jin Dal-rae, maternal uncle of Dan-dan, Dae-beom and Mi-rim. •
Park Ha-na as Jo Sa-ra :36 years old, has managed Lee Young-guk's household for five years; she has a crush on him. She is the biological mother of Lee Se-jong.
Supporting People around Lee Young-guk •
Cha Hwa-yeon as Wang Dae-ran :59 years old, Lee Se-ryun's biological mother. She is a former movie star and the stepmother of Lee Young-guk. She was Lee Ki-ja's middle-school classmate and later became the mistress to Young-guk's father at age 20. •
Yoon Jin-yi as Lee Se-ryun :36 years old, Lee Young-guk's younger half-sister, daughter of Wang Dae-ran. She falls in love with Park Dae-beom at first sight. •
Choi Myung-bin as Lee Jae-ni :14 years old, arrogant and rough eldest daughter of Lee Young-guk. • Yoo Jun-seo as Lee Se-chan :10 years old, eldest son of Lee Young-guk, likes hip-hop and swag. •
Seo Woo-jin as Lee Se-jong :6 years old, a cute kindergartener and the (supposed) youngest son of Lee Young-guk. •
Lee Il-hwa as Anna Kim •
Kang Se-jung as Kim Ji-young (who became Anna Kim after her accident) (cameo eps. 1 and 6) :Ex-wife of Park Soo-cheol and biological mother of Park Dan-dan. 10 years ago, she had a car accident and had dozens of major surgeries, she overcame all that and moved to the United States to succeed as a designer. Her mother had been Lee Young-guk's nanny many years ago.
People around Park Dan-dan •
Lee Jong-won as Park Soo-cheol :55 years old, husband of Cha Yeon-sil, the father of Park Dan-dan and stepfather of Park Dae-beom. He is a devoted father. Known as Kyung-Hoon as a child. •
Oh Hyun-kyung as Cha Yeon-sil :57 years old, daughter of Jin Dal-rae, wife of Park Soo-cheol, stepmother of Park Dan-dan and biological mother of Park Dae-beom. She likes drinking and dances and is full of
aegyo. •
Ahn Woo-yeon as Park Dae-beom :80 years old, mother of Cha Yeon-sil and Cha Gun, grandmother of Dae-beom, Dan-dan and Mi-rim. •
Kim Yi-kyung as Kang Mi-rim :25 years old, granddaughter of Jin Dal-rae, niece of Cha Yeon-sil and Cha Gun. Her mother is the deceased oldest daughter of Jin Dal-rae. Love interest of Bong Joon-oh.
Others •
Lee Hwi-hyang as Lee Ki-ja :59 years old widow, Jo Sa-ra's mother, Jang Mi-sook's high school classmate and Wang Dae-ran's middle-school classmate. •
Im Ye-jin as Jang Mi-sook :59 years old widow, Fantom clothing line store owner, Jang Gook-hee's adopted older sister and Bong Joon-oh's mother. •
Yang Byung-yeol as Bong Joon-oh :Jang Mi-sook's son, a kind and faithful medical student is good-looking and sweet. •
Wang Bit-na as Jang Gook-hee :40 years old, Lee Young-guk's college alumna and longtime friend, Jang Mi-sook's adopted younger sister. She emigrates to the USA. •
Eru as Ko Jung-woo :40 years old, Lee Young-guk's college alumnus, longtime friend and lawyer. • Kim Young-joon as Oh Kyung-seok : Son of the director of Sa-Rang hospital. He wants to marry Lee Se-ryun for the sake of the hospital. •
Lee Tae-ri as Ma Hyun-bin :He is the senior of Park Dan-dan, who is friendly and kind. Young guk is jealous of him seeing his close relationship with Dan-dan. •
Han Jae-suk as Oh Seung-ho :A friend of Lee Se-ryun from studying abroad. but he used to like her. •
Kim Ga-yeon as Mrs. Kim, housekeeper and the home maid at the home of Lee Young-Guk. • Yoon Ji-sook as Mrs. Yeoju, a housemaid, who secretly helps Park Dan Dan. • Jeon Seung-bin as Jin Sang-goo : Lee Se-jong's biological father and Jo Sa-ra's old lover. •
Oh Seung-ah as Ahn Ji-min, who has liked Lee Young Guk for long enough to be able to send emails even while studying abroad.
Special appearance • Lim Hye-young as Young-ae :Lee Young-guk's deceased wife (died at the age of 37), and mother of their 3 children. Jo Sa-ra's good friend. •
Hong Seok-cheon as Real Estate President •
Jo Eun-sook as Mi So-cheol's mistress :He comes to see the house where Lee Ki-ja lives. •
Moon Hee-kyung as Seung-ho's mother Ep.36-42. ==Production==