Chuu Hachikawa served as an Associate Special Class Investigator for the CCG. He possessed spiky grey hair, wore round glasses, and bore a permanently disfigured lower face – a lasting scar from an encounter with the ghoul gang Black Dobers ten years before the main story. This brutal incident also claimed his entire squad during an operation where they prioritized civilian safety, fundamentally warping his personality. Once duty-bound to protect civilians, the massacre ignited an intense hatred for ghouls within Hachikawa. This animosity drove his actions during the Owl Suppression Operation. Leading Squad 3, he deliberately shot both Kaya Irimi (the Black Dobers leader, "Black Dog") and an elderly civilian to wound Irimi, blatantly disregarding protocol. He dismissed criticism, consumed solely by vengeance until Ken Kaneki intervened, defeated him, and rescued Irimi. Hachikawa later faced Eto Yoshimura on a rooftop using a reserve Quinque. His bitterness extended to subordinates, notably displaying harsh frustration towards Tooru Mutsuki during the Torso Investigation and accusing him of incompetence. Hachikawa later investigated Rushima Island as a suspected Aogiri Tree base. Discovered by Eto, his team attempted retreat but was ambushed by Seidou Takizawa and Shikorae. Shikorae savagely bit off Hachikawa's nose during the assault. Disarmed and defenseless after Takizawa destroyed his Quinque, Hachikawa was impaled from behind by Shikorae and killed. His body was subsequently consumed by Takizawa and Shikorae. Hachikawa harbored a specific, decade-long grudge against Kaya Irimi, holding her directly responsible for his disfigurement and squad's annihilation. Their confrontation during the Anteiku raid revealed a complex history; Irimi recognized him instantly by the sound of his body and addressed him by the nickname "Hachi," indicating prior familiarity. Supplementary material hints at a deeper, potentially romantic relationship predating the Black Dobers operation. A theory, supported by symbolic imagery (an "X" mark on Irimi's stomach in chapter 131, a recurring symbol for hybrids), speculates Irimi may have been pregnant with Hachikawa's hybrid child. This theory proposes Hachikawa killed the child upon discovering Irimi's ghoul identity, fueling their mutual hatred. Irimi's final words, "See you in hell," implied shared damning knowledge. His relationship with partner Ayumu Hogi involved concealed care, evidenced by her mourning after his death. In combat, Hachikawa wielded the Quinque Kajiri, a golden gauntlet capable of firing crystalline projectiles. He demonstrated proficiency in close-quarters combat, successfully countering Irimi's attacks. Kajiri was destroyed twice: first by Kaneki during the Anteiku raid and later by Takizawa on Rushima Island. His abilities secured his rank of Associate Special Class Investigator. A trivia note indicates his name was partly inspired by Hachikō, the loyal Akita dog, reflecting Hachikawa's own persistent, albeit twisted, pursuit of vengeance against Irimi over nearly a decade – a namesake Takizawa referenced upon encountering him on Rushima.