Flower in a Storm Vol. 1 (manga)

Riko Kunimi is trying to lead a normal high school life when Ran Tachibana bursts into her classroom carrying a gun and tells her that her life is now his. Ran, the richest, most powerful 17-year-old in Japan wants her as his wife, and he's not taking no for an answer!

If Ran can't capture her by five o'clock the next day, he'll give up on her, but he has all that money can buy at his disposal. However, Riko has one trick up her sleeve--she has superpowers!