Shindou Koujirou is a highly-skilled negotiator working for the Ministry of Foreign Affairs. As his plane at Haneda airport prepares to take off, a huge mysterious cube appears from the sky. "It" expands rapidly, and absorbs the passenger plane and its 252 passengers.
The cube's name is "Kado".
A strange being called Yaha-kui Zashunina appears from within Kado and tries to…