In a strange turn of events, a young woman wakes up in an unfamiliar room, undergoing a perplexing physical transformation. As she grapples with her confusion, a mysterious message on a floating screen informs her that she is dead. Tasked with a seemingly impossible mission to kill someone named Otsutsuki Kaguya, she embarks on a journey to unravel the truth behind her predicament and find a way back to her own world.