Blue Birthday [Russian]

Kim Ye-rim

Oh Ha-rin

Hong-Seok Yang

Ji Seo Jun

Lee Jung-jae

Detective

Yoo Soo Bin

Senior at Seoyeon High School

Lee Sang-jun

Cha Eun-seong

Kwi Hyun Song

[Photo Shop owner]

Min Chae Yeon

Ha Rin's co-worker

Moon Ju-won

Ji Seo-jun (Young)

Park So Jung

Do Soo Jin [Young]

Kim So Yoon

Oh Ha Rin [Young]

Jeong Ye Dam

Ji Hye Min [Young]

Cheon Ji Won

[Hye Min's friend]

Park Joo-Hyun

Kim Eui Young

Kim Gyeol-Yu

Do Soo Jin

Kim Yi-Seo

Ji Hye Min

Lee Dong-Joo

Kim Shin Woo

Yoo Su-bin

Senior at Seori Highschool