Cielo

In his late twenties. He is Rosa's senior and educator. Chief warden. He's in charge of all the prisoners, but he's not in charge like the protagonist. He is also in charge of the guards. He is a calm and mild-mannered person who guides Rosa correctly at all times. To Rosa, he is a senior who she admires.

A few years ago, a new system for managing prisoners was introduced. He was one of the prison guards selected for the first test. He is kind to his colleagues, but his attitude towards prisoners changes so much that you would think he is a different person, ruthless and merciless.