Takua Arima is a young student whose father was a historian conducting various studies on the possibility of parallel worlds. One fine day, for reasons unknown, Takua"s father vanished without a trace. During the summer holidays, the young man receives from him a strange package and letter stating that with the device he has received, one can travel between parallel worlds. At first Takua does not take the contents of the message seriously, but soon realizes that it is true, and a criminal organization is hunting for the device. Now the hero must find his father and discover the true purpose of the device that has come into his possession.
