New teacher Ruri is deceived by students who appeared to be well-behaved, then forcefully raped. Drawn in by their words, she is treated like a pet. Used as an outlet for their youthful desires, she suffers secret groping during class, betrayal by a fellow teacher she trusted, and is restrained while her large breasts are toyed with. With a vibrator inserted, she can no longer endure the humiliating dog play, as relentless cruelty and degradation continue without mercy.