The Twin Sister I Knew as a Child

【No System + no rebirth + no golden finger + super sweet + yandere + everyday campus life】 When he was six, Su Bai met a pair of twin sisters in the countryside. He protected them like a real big brother, and they promised to live together when they grew up. Fifteen years later, the two girls really did get into his university. They showed up at his doorstep with suitcases, smiling as they called out, “Big Brother Su Bai.” The older sister is cool-headed and good at keeping house, and she can cook his favorite dishes. The younger sister is lively and affectionate, always hugging his arm and acting cute. Su Bai feels like the luckiest man alive. What more could he ask for than two adorable, thoughtful little sisters? But gradually, he starts to notice something is wrong... Why do the girls in his WeChat contacts keep disappearing for no reason? Why does his younger sister come home with red eyes whenever he talks a little too long with an upperclasswoman? Why does he always feel like someone's by his bed in the middle of the night, only to wake up and find nothing there? And what exactly are they hiding in that room that's been locked for years? As the looks in his two sisters' eyes grow stranger and stranger, Su Bai panics: “Wait! I'm your big brother!”