This is a story of a girl whose past had been a rude memory when a tragedy happens to her parents and sisters and she’s left all alone. During her sadness, she meets her childhood friend, her estranged older brother who threw away his family name in order to live a normal life and carried a heavy burden for abandoning her and her older twin brother who went missing after the accident. As they all realize how much time was lost, their meeting unleashes a whole string of memories as they find themselves recalling the times they spent with each other, the pieces of the past tightly bound by their friendship, relationship as siblings...and with each memory recalled, the sense of longing for the other grows quickly.

Choi Hyun Hoo

He shares childhood memories with Bae Min Seo and constantly tries to help her recover from the memories of the past. He eventually falls for her and helps her locate her older brother, Min Ha, who left her and her younger brother, Min Yeoung, who went missing after the accident. He is the one who helps his brother cope with the loss of his girlfriend who happens to be Min Seo's sister, Min Chae. 

Bae Min Seo

Hyun Hoo's childhood friend who lost her parents and sisters after an accident. Her older brother, Min Ha, threw away his family name and abandoned Min Seo and his family to live a normal life. Later, he carried a heavy burden for abandoning Min Seo.

Choi Hyun Soo

He is Hyun Hoo's twin brother who is also Min Seo's childhood friend. He happens to be the boyfriend of Min Seo's sister, Min Chae. After the death of Min Chae, he became a very cold and emotionless person and brother. He never wanted to fall in love ever again. But after seeing how Hyun Hoo loved Min Seo, he decides to open his heart for a new romance. 

Bae Min Ha

He is Min Seo estranged older brother who threw away his family name in order to live a normal life. But after the death of his parents and two younger sisters, he carried a heavy burden for abandoning Min Seo and his younger brother, Min Soo.

Bae Min Soo

Min Seo's older twin brother who went missing after the accident. He thought that Min Seo dissappeared so he went looking for her. In the middle of his search, he met a girl named Chun Hae Joo, whom he falls for.