Tatsuya and Miyuki are invited to a party to commemorate the completion of Japan's first hyper-building offshore tower, there Hayama introduces a young girl called Sakurai Minami. The two are shaken upon seeing her face which is that of a woman who died in an incident three years earlier. At such a time, there is intelligence that the party is being targeted by extremist magic advocates — The Advancement of Humanity Front.

The Advancement of Humanity Front have declared they will ‘blow up the offshore tower in one hour’. But there is no guarantee they will keep to their one-hour time limit. For the sake of preventing the Advancement of Humanity Front’s scheme, Tatsuya takes Miyuki and Minami towards the control centre on the first underground floor.