After failing to express his love when he was young, Su Yi's self-esteem was hurt for more than ten years. Years later, when he met the person he was passionate about again, he was accused of being in a different relationship. Chong Beiyang, a professor at A University, condensed the impermanent changes in the world into a sigh. Su Chongxi, who was known as a sigh, would have sighed all his life---if he hadn't met Su Yi who was in love with someone else. A sigh ended a secret love between you and me, and a sigh covered up an unspeakable misunderstanding and grievance. But fortunately, thanks to the misunderstanding back then, she didn't become a thorn in his side, and he wouldn't be rude to her!