The 70th chapter of the Toaru Kagaku no Railgun manga was released on April 26, 2014. The chapter reveals the secret history of Kouzaku Mitori, her friendship with Dolly, and her eventual start of darkness. By the release of the 10th volume of the Toaru Kagaku no Railgun manga, the contents of chapter 70 are later moved to the 68th chapter in the tankobon.