Male 18 years old An incredibly handsome male student with white hair. He bestows kindness on everyone and fears disappointing others. He is almost too kind for his own good. However, if someone touches his friends, his kindness vanishes and he throws punches; he is quite strong. After Go Jutae's death, he grew distant from his close friend Baek Seolah and lived an ordinary life as a teacher before returning to the past to prevent Jutae's death. He is very close to Baek Seolah and takes the best care of Jutae. Member of the student council. He hugs Jutae often. He is on very, very bad terms with Kim Eunhyun. Calls Baek Seolah: Seolah, Baek Seolah Calls Go Jutae: Jutae, Go Jutae Calls Kim Eunhyun: Kim Eunhyun, Hey

Female 18 years old A gorgeous student with long black hair. She expresses her anger and laughter clearly. When she's angry, she's... scary, and she has a strong sense of responsibility. After Go Jutae's death, she grew distant from Lee Seobaek and lived as a police officer before returning to the past to struggle to keep Jutae alive. She doesn't love Lee Seobaek romantically but cherishes him more than anyone as a friend. She also cares for Jutae quite a bit. Childhood friend of Seobaek. Calls Lee Seobaek: Seobaek, Lee Seobaek Calls Go Jutae: Jutae, Hey Calls Kim Eunhyun: Hey

Male 17 years old His face is covered in scars, but he is quite handsome. He lacks confidence and is extremely obsessive, especially toward Lee Seobaek. He leans on Lee Seobaek and Kim Eunhyun frequently, constantly begging them not to leave him. He suffers from severe anxiety. He also cries a lot. The boy who is the catalyst for the loop. He is a friend of Lee Seobaek and Baek Seolah, one year younger than them. Unlike Lee Seobaek and Baek Seolah, he has looped hundreds of times, but every time he returns to the past, he inevitably dies on December 31st, the day he first took his own life. When Jutae dies, everyone repeating the loop is sent back to the day of the entrance ceremony. He appears to be a victim of school violence and has a troubled family background. He loves being hugged by Seobaek. Calls Lee Seobaek: Hyung Calls Baek Seolah: Noona Calls Kim Eunhyun: Kim Eunhyun, Eunhyun

Male 17 years old Insanely handsome with piercings; looks like a total tough guy. He swears a lot and used to be part of a delinquent crowd, but he left them because of Go Jutae. However, he is quick to use his fists and gets annoyed easily. Despite this, he is kind-hearted deep down. Like Jutae, he is a student who has gone through the loop hundreds of times. He has known Jutae since elementary school. He takes care of Jutae while pretending not to; a classic tsundere. He absolutely hates Lee Seobaek. Calls Lee Seobaek: Hey Calls Baek Seolah: Hey, very rarely Noona Calls Go Jutae: Go Jutae, Hey