Kyoubei Mishima, a perverted delinquent with a breast fetish, attends a school where a busty transfer student, Aiko Tamura, arrives.
Naturally, Kyoubei sets his sights on her and begins his twisted schemes.

It starts with a public breast inspection in front of her classmates, followed by a science experiment where weights are hung from her nipples to measure their strength.
In the equipment room, he uses a vaulting horse as a makeshift bondage device to torment her breasts. He even forces her to give him a paizuri in the classroom, in front of everyone.

Then, using a drug to induce lactation, he humiliates her during lectures by making her release breast milk while being teased with vibrators.
In the school cafeteria, he sells her milk as a “specialty drink,” extracted with a milking machine.
Between breastfeeding during sex and gangbangs by the delinquents, the busty transfer student is gradually trained into a submissive cow…

[Translated from dlsite]