The Maebashi Prison (前橋監獄, Maebashi Kangoku) is one of the many prisons in Japan. It is located in the Gunma prefecture.
Maebashi Prison was built in the same style as the prisons of the Edo era, which meant that the walls were all made from wooden bars so that the guards could easily see into the cells. They were completely open to the elements as well. There was a toilet in the cell which was a bucket sitting beneath an opening in the floor. The guards collected the bucket by opening a little door beneath the cell and pulling it out.
Yoshitake Shiraishi came to Maebashi Prison after he had heard from a yakuza member that Sister Miyazawa may be here. He was immediately recognized by the guard and thrown into the prison to find out that the sister had never been to this prison. Because of his reputation, he was the only prisoner with manacles and a ball and a chain. He was able to break out by starving himself for several weeks so that he was thin enough to open the toilet lock with his foot and escape through the toilet hole under the cells.