In a dystopian nation, a unique public prosperity law is in effect: The National Welfare Act, under which citizens aged 18 to 24 are selected to die for their country. Twenty-four hours before a nanocapsule executes their death, the chosen receive notifications called "Ikigami" from government messengers. The government provides only one stated reason for the act’s purpose—to spread the value of life. Kengo Fujimoto is a newly appointed Ikigami messenger who is undecided about his stance on the act. To curb his hesitation and avoid the watchful eye of the national police, Kengo decides that delivering the Ikigami will help shape his opinion. Ikigami follows how people act knowing that their final hours are upon them. Whether committing acts of kindness or crimes of passion, the chosen's actions have profound impacts on those around them, and it will ultimately lead Kengo to his decision.