Kozuka was born in Nagoya. His grandfather, father, mother and aunt were figure skater so he was called "thoroughbred". He studied sports education at Chukyo University. His coach is Nobuo Sato and Kumiko Sato. He has very good skating skills. He is in good terms with Mao Asada, Miki Ando, Daisuke Takahashi and so on. He likes karaoke and goes to karaoke with Mao Asada frequently. His favorite food is grilled meet.