|Public Safety Bureau (former)|
|0115 The Town Where Sulfur Falls|
He has dark blue hair and eyes, and a child-like face.
Around 2102, Kozuki begins to work as an Enforcer.
He shares a close relationship with Aoyanagi, and it was hinted that he "effortlessly and painfully date with the Inspector." However, Kozuki still tries to flee and is killed by her under the direct orders of the Sibyl System.
Kozuki and Sasayama often play cards together and seem to be friends.
- He is younger than Aoyanagi, but has been working alongside her for many years.
- His seiyuu also voices Kirito Kamui.
|Akane Tsunemori - Mika Shimotsuki - Kiyoka Tedzuka|
|Shinya Kogami - Tomomi Masaoka - Nobuchika Ginoza - Yayoi Kunizuka - Shusei Kagari - Mitsuru Sasayama - Sakuya Togane - Sho Hinakawa - Kaede Hasuike - Teppei Sugo - Kenta Yatsuka - Ryoichi Naito - Ryunosuke Hirako|
|Risa Aoyanagi - Mizue Shisui - Masawa Shimomura|
|Ryogo Kozuki - Akira Yamatoya|
|Moe Suzuki - Shuichiro Domoto - Yoshitoshi Waku|
|Kaname Shinjo - Tetsuya Hyodo - Tsubaki Aikawa - Takayuki Haga - Koichi Hatano - Mai Momota - Ayaka Takami - Naoto Kurata - Hina Amari - Tsubasa Torii|
|Shion Karanomori - Joji Saiga - Maru|