It’s Tough Being the Male Lead’s Stepsister

(Both leads are each other's only partners, one-on-one romance. The male lead won't fall for the original heroine, and both are pure in body and mind.) First world: High school romance. Second world: Undecided. The heroine looks sweet, adorable, and innocent, but inside she's constantly complaining and secretly rather lecherous. She's also extremely superficial. The male lead is sarcastic. You might think he has it in for you, but in reality, he can't stand anyone. You could say he's exactly the same inside and out. Later on, his personality gets a little unpredictable because he has memories from different stages of his life. Dropped. Don't read.