NEXT is a secret organization in that is focused on turning Cursed Children into elite assassins.
The overall history of NEXT is left unknown but the organization's leader, Ayn Rand, was part of it for a period of time.
Barely anything is known about NEXT other than that they are a secret organization. The leader is Ayn Rand who had been an American scientist that specialized in the New Human Creation Plan. He eventually had Tina Sprout be sent to Japan where she was to assassinate Seitenshi, the Protector of the Tokyo Area and this lead to an armed skirmish with members of the Civil Security Corporation. Eventually however, Tina had left and instead she joined up with Civ Sec. The current status of NEXT is unknown.