Cinderella Game.

Sana Haitani (Kasumi Yamaya) is a member of an idol group. She's following the dreams of her now deceased older sister who always wanted to become a top idol. Unfortunately, Sana's idol group is disbanded. She is then kidnapped and taken to an uninhabited island. What awaits for her is a card battle. If she wins in the card battle against other kidnapped idol girls, she can become a top idol. But, if Sana loses ... she will die.