If I Don't Sleep with the Male Lead, the World Will Be Destroyed

One-line summary: The moment her hair tie comes undone, she blushes, goes weak in the knees, pounces on him, and takes the lead! Synopsis: Fu Xin is known as the #Liangjiang University's smartest and most ruthless student council president ever#. During military training, she was the one who mercilessly took a pair of scissors to future campus heartthrob Luo Jinkun's beloved long hair, cutting it down to a buzz cut! She was the one who mercilessly tossed the campus belle's skirt aside and covered her pretty legs with baggy camouflage pants! And she was the one who mercilessly dragged every student without a school badge to the flagpole, made them hold their badges high, and swear an oath like idiots! Fu Xin's misdeeds have enraged both gods and men. They are too numerous to list. Until one day, Luo Jinkun discovers the student council president's weakness. The moment her hair tie comes undone, she blushes, goes weak in the knees, pounces on him, and takes the lead! Fu Xin was a time-space researcher from the future, rigid, preachy, and boring. Then one mistake triggered a time-space disturbance, sending her into the book her junior apprentice was reading, The Rich Old Man's Pregnant Wife. She finds herself sitting in the college entrance exam hall. And sitting behind her is the younger, deadbeat-student version of the "old man." She is also bound to a countdown nuclear bomb System. If she doesn't sleep with the old man before the deadline, the whole world will explode with a bang. So, for the sake of world peace, she shifts her exam paper to the side. Who knew she'd get into Liangjiang University, only for the guy to have no memory of her at all? Fu Xin, expressionless (she has no idea how to date and is freaking out) System: Don't worry, I'll help you. A chaste, top-student beauty on a pedestal vs. a scheming "old man" who waits patiently for his prey Actually, this is a story about how knowledge changes your fate. Ahem.