Rammed by a Ram

In a society where carnivores feed on weak herbivores, Nen, the leader of the revolution, takes in a small black lamb. Despite being a fierce carnivore, the lamb shows no fear towards Nen, and becomes his right-hand man on their mission to equality. One day, a mysterious parcel arrives, and the lamb offers to help Nen relieve his stress. Has he finally grown enough to make a bottom out of his beefy leader!?