Lizzy has just landed an amazing part-time job that allows her to live in a lavish mansion but not everything is what it seems as she realizes the house's mysterious owner is a splitting image of herself. And the mystery continues to deepen as suspicious characters begin to enter her life who may not be who they say they are...

(Source: MU)

From Strawberrie:

As a child, Joon-young was always teased because his mother owned a bar that served Americans. When he meets Hae-in, a blind girl, they become childhood sweethearts and he vows to always protect her. However, Hae-in and her mom take off one night, leaving Joon-young and his promise behind. Hae-in later meets Gun-woo, the rich son of a CEO. Among these three, a tragic love triangle begins to form...

Do the math--in a high school male dormitory room, there are four bunk beds…but five boys! Will these five hot dudes--Mi-Oh, Chi-Young, Jay, Ji-Myung, and Il-Yong--be able to make the best of the tight situation? Follow them as friendships--and possibly more--begins to develop among them!
(TOKYOPOP)

As a child, Joon-young was always teased because his mother owned a bar that served Americans. When he meets Hae-in, a blind girl, they become childhood sweethearts and he vows to always protect her. However, Hae-in and her mom take off one night, leaving Joon-young and his promise behind. Hae-in later meets Gun-woo, the rich son of a CEO. Among these three, a tragic love triangle begins to form...

There is also a Korean movie with the same title and plotline.

Noa doesn't have a father. She lives together with a working mother. That's why she always hoped for a sibling. One day her mother brings Mizuki and Akari to live with them. Noa is extremely happy with that, but why does Mizuki always show an unhappy face? Will Noa's dream for a sibling come true?
(Source: Shoujo Crusade)

From AtoZ:
School will bring a fresh start and a way to break free from her seemingly cursed fate. Disaster strikes before she even arrives for her first day at school and a most embarrassing secret is discovered by Chun Hyuk, an aspiring band vocalist who loves only money and music. Can Yu Goon Goon and her best friend, Da-Jung, find a way to shut the mouths of Chun Hyuk and his fellow band members before her high school life is ruined? Da Jung wants to make a deal with the guys but how high a price are the girls willing to pay?

She is beautiful, persevering but what amazes people is her sharp mind. Sharp minded enough to become the next empress. However the prince despises her... How will she manage to make him fall in love with her ?

All Kum-Ji wants in life is to meet her favorite boy band, DDL. When she finds that the roster for the fan club is full, Kum-Ji despairs on ever having the chance to meet them face to face. Just when she believes all hope is lost, she decides to con her way into the boy band circuit by faking an interest in another band, Yo-I, and joining their fan club. Once in, she will have access to other bands, including her beloved DDL, who often plays the same shows. However, the best laid plans so frequently go awry, and her deception is very quickly discovered by one of the band members, E-Soh. E-Soh originally decides to blackmail Kum-Ji into doing whatever he wants, but he never planned on falling in love!
(Source: Wikipedia)

From Yen Press:
A spoiled brat from a wealthy Japanese family, Tsuyoshi is unceremoniously shipped off to Korea by his strict grandfather who tells him the family secret — they’re Korean! Sparks fly when the resentful high schooler arrives at the airport and shares an impromptu cab ride with Kang Be-Ri, a plucky girl who happens to be his new neighbor. Will the two ever get past their differences? And will Tsuyoshi learn to accept his new destiny?