The Demon King's Stopwatch

Kazuko Tokio, an average, nerdy boy with a scrawny build had an interesting first day of University. He was nearly beaten to death, saved by a beautiful girl, and then... Time stopped. [Tutorial will forcibly process] [Demon King's Skill: Stopwatch Lv. 1 Has Been Activated... For the Tutorial, Skill will temporarily change] [All Time will be stopped for 5 minutes] His quest? To make the beautiful girl who saved him climax. Inspired by Sex Stopwatch, the H-Manhwa Tags/Warnings: - Smut/R18: This is a 40/50% Smut, 50/60% Plot/Slice of Life Fic - Harem: MC will have multiple women. After all, it may be against Human laws to have more than 1 wife. But as a demon, human laws don't apply, do they? - Weak to Strong/OP MC: MC starts off weak, then with his system becomes strong and OP