In the anime and manga series Jujutsu Kaisen, a Star Plasma Vessel is a person who is capable of merging with Tengen, an immortal sorcerer, and stopping their evolution into a being with diminished self-awareness, whose ego extends beyond the body and becomes one with the world. Tengens body wears down and ages the longer theyre alive, resulting in them needing to find a new vessel every 500 years. The Star Plasma Vessel is a young woman who possesses the potential to refresh Tengens immortality by merging with them. Once the merging is complete, the vessel loses their existence and identity, being unable to do anything on their own, which is no different from sacrificing their lives. The vessels can communicate with each other, even though Tengen cannot communicate with them. Only two vessels have appeared in the series so far, Riko Amanai and Yuki Tsukumo.