Product description ※Please note that product information is not in full comprehensive meaning because of the machine translation.
One day, before the 57 th Off-Wall Survey, a small-scale off-wall survey activity was conducted.
More than a dozen members of the Investigation Corps, including the main character, were to search the vicinity of the' old castle' under the direction of the head of the Investigation Corps.
However, when the old castle was near the end of the last forest, the giant raided, the ground collapsed in confusion, and the members of the Investigation Corps fell into the basement of the old castle.
The main character, who woke up in the lowest layer of the basement, was unable to reach the ground due to the failure of the three dimensional mobile device. The main character, together with his only partner, was able to find the mysterious underground facility and escape from the dead ground.