G-cup female teacher Sayuri indulges daily in lewd fantasies about herself in the empty classroom after school. Her passion grows stronger each day, until she can no longer suppress her urge to be bound and intensely punished. Completely dominated, she is reduced to a state drenched in saliva and arousal, utterly overwhelmed by pleasure. Her appearance is that of a true "cow slave," completely submerged in extreme ecstasy.