The protagonist is a teacher at a small kindergarten. One day, he gives the girls special cookies that cause extreme physical growth. Overnight, the innocent little girls develop mature, hyper-voluptuous bodies with massive breasts, wide hips, and thick thighs — yet their personalities and knowledge stay purely childish and naive.

In Growth.1, the girls continue acting exactly as before: playing, hugging, and clinging to their teacher with their new adult bodies. Their unconscious movements and innocent physical contact become powerful temptations. The teacher struggles to hold back as he faces endless unintentional seduction from the plump, jiggling bodies of his former students.

In Growth.2, things escalate further. The teacher begins giving "massages" that quickly turn intimate, groping and sucking on their breasts under the guise of care. The other girls watch curiously and soon join in, their complete lack of sexual knowledge making their lewd actions even more arousing. The story highlights the extreme contrast between their erotic, adult physiques and their pure, ignorant minds, leading to intense erotic situations.