I traveled through hundreds of worlds at once

It was built before the Gastrula War, but humans were defeated and forced to evacuate before it was officially used during the Gastrula War, and it was left outside the area for a full ten years.

Until the beginning of the Black Bullet plot, Satomi Rentaro used the weapon to defeat the invading gastrula in stage five, but because the weapon was originally designed for use in space, it was eventually scrapped due to irreparable damage.

Ten years later, even the most perfect machinery and buildings should be damaged, but as a top-secret weapon, the ladder still has enough power to use ten years later, which means that the top leaders of the Tokyo District have never given up on the ladder.