500 Million Year Button(2022)

500 Million Year Button is an anime series that follows three siblings facing a desperate choice. Tonio, Jaibi, and Suneko need money urgently to pay for their father's hospital treatment. When a mysterious stranger appears with a peculiar button, they learn its rules: press it and receive one million yen instantly. The catch is brutal—the person who presses it must spend 500 million years alone in an empty void. Once that incomprehensible span of time passes, their memory erases and they return to the moment before pressing the button, experiencing no subjective time at all. For the desperate siblings, the button represents both salvation and an impossible moral dilemma. The series explores what lengths people will go to save those they love, and the weight of choices made under financial desperation.