In every timeline, a magic-less human named "Yuu" is taken by a mysterious black carriage and wakes up at Night Raven College, stranded in an entirely different dimension from their home universe. Every Yuu has their own differences-different looks, different personalities, different backstories, even different names. Despite these differences, however, there is one thing they share in common: they're all, to their very cores, good people inside. Right?

Y/N, a simple woman, joins the deadly games to pay off debts after her mother's death. Young-Il, a heartless soul, controls the games, watching everything from afar while sipping on his glass of whisky. But this year is different. When he spots Y/N, number 160, during the game of "Red Light, Green Light," he can't help but grow more obsessed with her. The first game ends, and Young-Il decides it's time to join the games himself, meet her, and make her his forever. Not that he will allow anyone else to even look at her But will Y/N really trust him?