Yuu, a career woman, harbors a dark secret unknown to anyone. Possessing intense sadistic tendencies, she has imprisoned her former subordinate—a male masochist—in her apartment, completely stripping him of freedom. She forces him to wear full-body black pantyhose, binds his limbs tightly with duct tape, and keeps him as nothing more than a human grub, treating him as a living toy. She never allows this grub man to leave the room, keeping him bound even when she goes to work or out, leaving him alone for long hours and giving him only her own urine as hydration. To relieve her daily stress, she repeatedly subjects him to brutal treatment: crushing him underfoot, kicking, punching, water torture, whipping, anal stretching, and forcing continuous ejaculation under the pretense of extracting toxins. Whenever she has free time, she makes him lick her genitals, using him solely as a sexual tool. Every day after work, Yuu returns home with rising excitement, eager to torment her helpless grub man—who has been officially missing for the past two years.