For Whom (誰がために Ta ga Tame ni) is the 156th chapter of the Prison School manga, serialised in Weekly Young Magazine on October 27th, 2014 and published in tankobon format in Volume 16 on March 6th, 2015.
Kate is happy about Mitsuko's news : She heads over the prison immediately. Risa enters her rooms, but doesn't saw him at first, though she finally found out that he is kneeling in the room while still attached to the bed. She violently beat him until he falls, returning the bed normally in the process. As she is lying on him, she decides to rest like that a little.
In the prison, all the escape items have been discovered and put on the table as Mari confirms to Mitsuko they are all there. Kiyoshi realizes the failure and it consequences : the Wet T-Shirt contest will falls with the USC as the latter will be disbanded. He also remembers all the "humilitation" with a girl he has suffers to make the plan work with a defeated 'air.
He subsequently tells Mari it her fault as she didn't listen to him when he says the plan wouldn't work and it result in everyone's work to waste and the impossibility for him to ask for their forgiveness.
However, Mari reassures him that he did fantastic and have nothing to apologize. She he must continue to do his job. As Kate is entering the prison, Mari tells him they gotten Kate to show herself and that the 'real work begins' since Kioyshi perfectly execute Mari's orders all the time.
In the Boys's room, Shingo thinks they would have been screwed if Gakuto hasn't found out about the SC's plan, and that they would have to built the 'PBR mark 2' the next day as Gakuto is looking at the sky.