So far, more than 20 naked beauties have been sacrificed in the "Ma○ko Device Bondage". This is the first time in its long history that two people will be tortured together in a double iron restraint torture. Yui Hatano and Hibiki Otsuki are held captive in real iron restraints that have been passed down since ancient times. The two good friends torture each other, and are tortured at the same time... This feast of madness becomes more chaotic than ever, and takes the masochistic nature to even greater depths. Who will have their pussy awakened first?