She suffered from advanced gastric cancer, so she hid everything and broke up with him heartlessly in exchange for a worry-free future for him.
He hated her for three years, blamed her for three years, and watched her withering away with cold eyes.
It wasn't until she passed away that the truth was revealed, and he realized that he had hated the wrong person and had missed his life.
From then on, she slept forever, he regretted forever, his love was still warm, and he was in pain for the rest of his life.