In Jujutsu Kaisen, all living beings emanate an energy called Cursed Energy. The Cursed Energy arises from negative emotions that naturally flow throughout the body. Normally, people cannot control this flow in their bodies. As a result, they continually lose Cursed Energy and cause the the birth of Curses. Curses are a race of spiritual beings whose primary desire is to bring harm to humanity. These curses are shown as gruesome monsters.

Jujutsu Sorcerers are people who control the flow of Cursed Energy in their bodies.  High-ranking Sorcerers and Curses can refine this energy and use it to perform Cursed Techniques. An advanced form of Cursed Technique is Domain Expansion. User can use their Cursed Energy to build a pocket dimension that covers the surrounding area.

Yuji Itadori consumes the rotting finger and becomes possessed by a Curse known as Ryoumen Sukuna. He believes in leading everyone to a proper death and wants to save everyone.