Workroom A is one of two workrooms in the prison. Access to these workrooms is heavily regulated through sensors that react to bracelets attached to inmates, sending an electric shock to any prisoners who try passing through without permission. The animals used in the prison's animal therapy program can freely travel past these sensors due to tags that cause the doors to open for them. Despite this security, in March 2019, Manosuke Naitō was found murdered in Workroom A mere days after being arrested and detained in a detention center holding cell.