Im YoonAh _ Kim Yoona

-sweet,cute,caring

-childhood friend of Sungmin

-daughter for Taeyeon and Kangin

Lee SungMin_Choi SungMin

-handsome,caring,smart,good in sport

-childhood friend of Yoona

-confuse about his own feelings

-son for Siwon and Tiffany

Kim JoonWoon/Yesung _Kim Yesung

-a popular boy in the school,good looking,nice,rich

-likes Yoona as a sister or more than that...?

-cousin for Lee Sunny

Kim TaeYeon_Kim TaeYeon

-mother for Yoona,wife for Kangin

-cares about her husband and yoona alot,nice

Kim YoungWoon/Kangin_Kim Kangin

-father for Yoona,husband for Taeyeon

-a hardworking businessman,loves his famiy

Choi SiWon_Choi SiWon

-father for Sungmin,husband for Tiffany

-a strong man,likes to joke,business partner of Kangin

Tiffany Hwang Mi Young_Choi Fany

-mother for Sungmin,wife for Siwon

-sweet,act Yoona like her own child

-Dislike Sunny

Lee Sun Kyu/Sunny_Kim Sunny

-cousin for Yesung

-Likes Sungmin

-Flirty,evil,hate Yoona

Jessica Jung Soo Yeon_Jung Sica (appear almost the end)

-ex girlfriend of Sungmin

-leaving Sungmin for some reason