My Stepbrother Is My Secret Master

DramaBox synopsis

She's been his obedient pup for two years—blindfolded, collared, loyal. But she's never seen his face. Then she moves in with her stepbrother, Adrian. His voice. His commands. The blindfold. All familiar. He becomes her professor, and the lines blur further. When a jealous classmate locks her in a sub-zero freezer, he tears the blast door open to save her. Waking in the hospital, she sees the truth: professor, stepbrother, Master—one man. Two years of secrets. No more masks.