Marriage Purple - Manhwa

Rin Suzumiya is accepted into her dream high school, only to find herself in the same class as Yukichi Sakamoto, a despicable bully from their elementary school days. Despite their three-year separation, Yukichi hasn't changed a bit. When he demands her to write her name on a piece of paper, she complies just to get rid of him. But to her shock, it turns out to be a marriage registration form! And now Yukichi refuses to give it back unless she spends the next three years avoiding him. How will Rin survive high school now that she's bound to this tyrant?

This is the physical copy of the Marriage Purple manhwa.