Choi Seung-yoon as So-young

Ethan Hwang as Dong-hyun

Dohyun Noel Hwang as Child Dong-hyun

Anthony Shim as Simon

Hunter Dillon as Harry

Jerina Son as Mi-sun

Kang In-sung as Won-shik / In-shik

Choi Jong-ryul as Grandpa

Lee Yong-nyeo as Grandma

Vanessa Przada as Ashley

Tristan Ranger as Jackson

Aiden Finn as Eggers

Kendra Anderson as Miss Jane

Ryan Robbins as Mr. Murray

Eric Keenleyside as Principal Lafferty

John Cassini as Dr. Rydell

Sean Poague as Mr. Davis

Bryce Hodgson as Larry

Joshua Morettin as Pete