Kouzaburou Touma was the person behind The Specimen Case a few years before the series started. He worked as a teacher before he became a member of Sibyl.
Touma was a teacher at Oso Academy before he began taking an interest in killing. He was the person behind the murders in the Specimen Case, and was more notibly responsible for the death of Sasayama Mitsuru, a detective who worked at the MWPSB.
After committing gruesome murders through the use of Plastination, he was finally captured after he killed Sasayama. However, behind closed doors, the Sibyl System was planning on making him their new member. Though puzzled at first, Touma states that he quickly realized its splendor. Following his acceptance, his brain was removed and his body was discarded.
At some point before his arrest, Touma was acquainted with Shogo.
When Makishima is finally arrested by the MWPSB, he is put on board a transport aircraft, along with Joshu Kasei and a couple of drones. Using a copy of a book he once burrowed, it took little time to reveal to Makishima the identity of the current possessor of Kasei, who was Touma, requested to be the one to talk to him due to their past relation.
"Touma" then begins to explain the nature and true form of Sibyl, and uses the footage recorded by Choe Gu-sung to show this. As he continues to try and convince Shogo to become one with him as Sibyl's members, he accidently reveals their location, and that they are not at the NONA tower.
Due to this, Shogo begins to beat up Touma, just before he was about to fire a Dominator at him. As his legs are broken and his body thrown against a wall, Shogo explains that he wishes to 'continue living this game called "life" forever', before smashing his head in and opening it up, along with asking, if Touma is still afraid of death despite gaining 'the perception of God'.
The aircraft then explodes, and falls to the ground. At the crash site, only the destroyed body of Kasei is recovered, while another body emerges from a car that has just arrived, in order to talk to the newly-arrived Unit 1.
- He was born on the 25th of December 2084.
- He has a twin sister whom he called "princess". Both him and his twin were nameless, therefore their mother called them "prince" and "princess" .
- The "prince" entered a school called Touma, hence he was named Touma Kouzaburou based on the school he attended.
- Touma was the one who killed Sasayama by stabbing his lung with his pen before dissecting him alive.
- Just like Makishima, he too was a criminally asymptomatic person as he managed to keep his Hue clean.