The Atypical Young Lady Has Returned

The eldest daughter of the Yan family, Yan Jinyu, who has been missing for 16 years, has been found. She is brought back from an orphanage by her fiancé, the Second Master of the Yin family.

That year, Miss Yan was 18 years old.
…
The Yin family was one of the top families in the capital.
Second Master Yin's full name is Yin Jiujin. People call him Master Nine. He's 24 years old and has made a killing in the business world.
Master Nine follows his grandmother's wishes and finds the eldest daughter that the Yan family has long given up on searching for. He brings her home to raise her himself.
…
Yan in the eyes of outsiders: "Good figure, good looks, high intelligence"
Yan in the eyes of a friend: "The girl-next-door (That's weird). She's cold and ruthless."
Yan in the eyes of Master Nine: "She's young and inexperienced. She doesn't look like an 18-year-old at all. She looks wild and evokes a sense of pity towards her."
…
Those people who think that the eldest daughter of the Yan family is an unpresentable country girl are all slapped in the face.
Master Nine imagines that the person he brought back is a silly little girl. Gradually, he realizes that the little girl is sometimes quite cool and very strong.
Everyone believes that she has no backing and is just a lonely little pitiful girl. Unbeknownst to them, she has a few companions who have gone through life and death with her countless times. Together, they've built an amazing venture.