| Spoiler warning! This article contains plot details about an upcoming episode. |
Koshiro Okazaki is one of Hajime Kindaichi's childhood friends going to Fudo High School. He first appeared in Graveyard Island Murder Case as a suspect in the case, along with classmates Takeshi Jinma, Chie Hirashima and Remi Morishita. He later appears in House of Games Murder Case as a background character and in a flashback case, Campsite's Mysterious Case.