Cero works part-time at Spirytus, a legally-operating torture contract company, where he is known as the ace due to his high proficiency. He maintains positive relationships and gets along well with everyone in the workplace. Each day, he performs tortures alongside his senior colleague Shiu, an activity he enjoys as part of his everyday life. The environment at Spirytus is relaxed, homely, and easy-going, despite the nature of its business, and the company only targets individuals deemed evil. Cero is a smoker and works alongside other part-time employees including Shiu and two new hires named Mike and Hugh.