It is not Tag. It is not Battle Royale. It is Battle Royale Tag. Sena walks up to the school rooftop to return Yudachis handkerchief. Yudachi is not there and Sena falls asleep waiting. It is dark, she is confined and locked up at her school when Sena wakes up. The school has turned bloody red and the girls have to fight to the death. Who will survive the carnage is up to the girls.