The New Generation, or just New Gen, of kijikaiaku came some time after the war ended and the world was calmer again. Humans were mostly dealt with as Gaia wished, and those that remained were largely in hiding.
The New Gen were taught of the war, and why it had to happen, but they never experienced it themselves. Interested instead in moving towards the future, they sought to learn of the world all they could, driven by curiosity and wanderlust.