Zac Ayanokouji, Kiyotaka's older Half-Brother attending ANHS together with him. Just like Kiyotaka he was raised in the white Room and has been together with him since childhood as part of the 4th Generation, together being called 'Masterpieces of the white Room'. With the White Room being shut down for 1 year they saw this as a chance to escape their Father's claws and with the help of Matsuo (their Butler) flee, after that they started Attending AHNS. Before attending, Matsuo gave them the Information of the S-System and they came up with a funny idea (only for them obviously), Why don't one of us places in a lowest class while the other in the highest? Supporting each other and playing with their new 'tools', the interesting School life of the brothers begins.