The mysterious mastermind for the Hijacking Bus Incident on December 21st.

Spoiler

He is the main antagonist in Punchline. He is a leader of the Qmay Group and is a "W". Apparently, he is in charge of everything regarding the project to hijack Meika's hacking of the US satellite. He is the mastermind for the Hijacking Bus Incident, and the real identity of Gliese. He is currently on the run from the police.

Spoiler

His true identity is Guriko, the third child at the Uber Lab with Pine and Chiyoko. During the accident, Guriko's soul ended up in Pine's body which was taken back to the lab by the Qmay Group.

(Source: Punch Line Fandom)