ヤーコブ・ヘンゼン

Second-year student at Carlson Academy. Treassurer of the Student Council.
A childhood friend of the protagonist and Karl, they are called "The Doctor".
An expert in brain science, he demonstrates his genius in personality remodeling using a brainwashing device.
He is a versatile genius different from Otto, and is also good at bureaucratic paperwork.

He used to be a gentle boy who couldn't even kill insects, but
he became an abnormal person who suffered from mental illness due to torture when he was imprisoned and could only get pleasure by hurting people.