In My Sister's Devious Plot, you're a 20-year-old searching for your missing dad, though everyone thinks he's gone. You're sure he's alive because he's tough. Meanwhile, you're focused on caring for your younger sister. Unbeknownst to you, she's scheming to introduce other girls into your life. As you juggle taking care of your sister, attending to these new relationships, and investigating your dad's disappearance, you'll uncover the reason behind her plot.