Koji Kiyohara (清原 幸治 Kiyohara Kōji) is a tertiary antagonist featured in Crazy Diamond's Demonic Heartbreak, a spinoff manga of JoJo's Bizarre Adventure. He is a university student who shoots Josuke and random civilians of Morioh with a crossbow.
Kiyohara has dark, neck-length hair that is slicked back. He has a wavy strand of hair dangling over his forehead on each side. He has small irises and a wide nose. Kiyohara wears a puffer vest on top of a hoodie, baggy pants, and boots. He also wears a watch on his left arm and carries a backpack along with a quiver for his crossbow.
Kiyohara is a narcissistic and sadistic man who takes pleasure in hunting strangers as if they were animals. He believes that he's special compared to others around him and thinks he is the only one with the right to kill people. His ego is hurt when a random teenager like Josuke interferes with his plans.
Hiding in a subway station, Kiyohara starts indiscriminately firing arrows at civilians who are running away from an illusionary military helicopter produced from Petsounds's Stand. After he happens to shoot a kid in the neck who was running past Josuke, he also fires an arrow at Josuke's back. Enraged, Josuke dashes toward Kiyohara in order to stop him. Kiyohara shoots another arrow at Josuke but Josuke easily deflects it with his Stand, surprising Kiyohara. As he wonders who Josuke is, he continues shooting more civilians in the back. He fires at Josuke again and nearly pierces his forehead but Josuke's Stand grabs the arrow in time before it could go further.
Hol Horse fires two bullets with his Stand, blowing off Kiyohara's ear and a fragment of his crossbow. Petsounds starts flying away, momentarily distracting Hol Horse and Josuke which allows Kiyohara to run away. Hiding in bushes nearby outside of the subway station, he waits for Josuke to follow his blood trail while he aims his crossbow. However, Josuke had used his Stand to restore the fragment of the crossbow that broke off and used it to track Kiyohara. Kiyohara is stunned as he hears Josuke's voice behind him along with his crossbow suddenly being restored. Before Kiyohara could react, Josuke pummels him with punches using his Stand. Josuke steals Kiyohara's money from his wallet and examines his ID. He then ties up Kiyohara to a nearby tree using the string from his crossbow. Josuke's grandfather arrives soon after, so Josuke tells him to arrest Kiyohara. Acting like a police officer, Josuke charges Kiyohara with "assault with a deadly arrow".
- “Shooting those little brats... It felt so right!! I knew it! I was special all along!!”
- “No ordinary guy can hunt human beings like animals... I'm the only one with that privilege! And yet, some little shit has the gall to hurt me?! Damn it all to hell...!!”
- “You know to find me by following the blood trail, don't you? Kekekekekeh... Too bad you won't be finding me at the end of it!”
- “The second I lay eyes on you, it's game over, kid! This baby's gonna hurl a bullseye straight through your stupid mug!”