Characters 

TEN (21 years old)

loves to dance (since he was a kid) a vampire  handsome and cute; attractive regardless of gender  always popular at school; never alone  joins as new NCT U member 

TAEYONG (22 years old) 

original member of NCT U  a human has mysophobia (excessively clean)  doesn't like meeting new people  not many friends (excluding the members)

JAEHYUN (20 years old) 

a vampire  original NCT U member attractive, popular among girls  well-acquainted with Ten's family  loves Ten; almost in an obsessive way  loves to fool around 

DOYOUNG (21 years old) 

original NCT U member  a human that knows about the vampires  close friends with Ten and Jaehyun (since childhood)  Jaehyun's "food" when it is urgent 

YOONA (29 years old) 

a psychiatrist ; Ten's older sister gets "food" from her patients while comforting them  always worried for Ten  beautiful and attractive