Mimasaka Koushirou is the doctor that took care of Kanako after her surgery.
Kyogokudou said that Profesor Mimasaka was a scientist who had been doing experiments during the Second World War. He wanted to create a 'mechanical human' in order to make Japan succeed in the war. But, because it cost too much money, he was not able to do it.
It is revealed that his wife was Mimasaka Kinuko, the mother of Yuzuki Youko. Kinuko, even though professor Mimasaka took care of her, wanted to get divorced. Then Youko, who was in love with her father, tempted him and they had a daughter: Yuzuki Kanako, whose parentage was kept a secret from her.
Mimasaka created the giant box with machines based on his ideas of a mechanical human. A human´s head was put into the box and the machines ran the functions that are normally done by a human body.
Kanako was put there after the accident by Mimasaka who cut both her arms and legs (even though Youko disapproved), then put her into the box and gave it to a worker to be transferred to another place. But Amemiya san found it, killed the worker and took Kanako away.
Kubo Shunko then approached Mimasaka after having killed lots of girls trying to imitate Mimasaka's work. He asked to be put into Mimasaka's box.
At the end, when escaping with Youko and Kubo (in the box) Mimasaka was killed when Kubo came out of the box and bit him which caused Youko to kill Kubo in vengeance.