*Kwon Yuri 

-She has 2 older brothers and one older sister, she get along well with her brothers more than her sister.Yuri's life getting harder after her brothers start studying in university.Now she is alone only with her mother,father and sister.Her mother and father are busy with bussinessing.While her sister busy with studying.

*Lee Donghae

-He don't have sibling and his parents are bussinessing just like yuri's parents.His life kinda because he had no siblings to play with,no parents who cares about him,because they are really busy.There is some empty spaces in his heart,he feels lonely, maybe this is the reason why he is playboy. 

*Lee Jong Suk

-Yuri's cousin.They are reallyy reallyyyyclose since forever.Jong suk always take care of yuri after her brothers got into university.

*Im yoona

-Yuri's bestie since kindergarten because her house is only behind Yuri's house. Has a boyfriend name Choi siwon

*Kim Taeyeon

-Yuri's deskmate in highschool

*Park shinhye

-Same as Im yoona,they live together in the neighbourhood.yoona,yuri and her always sleep at each other house coz their parents usually need to go oversea to expanding their bussiness.But park shinhye parents are Doctors. Her parents need to stay at the hospital most of the time.

*Kwon Hyuk(Dean) and kwon hyukjun

-Yuri's brothers

*Kwon Bo Ah

-Yuri's sister

*Eunhyuk,kyuhyun,yesung,leeteuk,heechul

-Donghae's friends