On a deserted island in the sea, two survivors of an airplane crash have been awaiting rescue for three weeks, and are joined by three survivors involved in a boat accident. Pushed to their limit, the group decide to create distance between themselves and share food in order to survive. Until one day, the dead body of Ichinose, one of the survivors is found washed up on the beach.

"To those of you who lack the courage to die alone. Shall we die together? I'm waiting for those who are interested to contact me." Date: XX Month, 20XX. Somewhere in Tokyo. - Inspired by a post on a certain social media, six people seeking to end their lives gather. At the arrangement of the organizer of the suicide meeting, they will have a final dinner before leaving this world together before dawn. However, it turns out that the six cannot die together; the organizer is discovered as a corpse. Did the organizer commit suicide? Or... was the person murdered? Amid various speculations, the remained five begin to debate.