S1, E4: Tang Xin, dressed in her 'battle gear', boldly confessed her feelings to Tang Yu in his office but downplayed her affection, claiming it was a fleeting crush. Tang Yu, frowning, rejected her, stating they weren't suitable. Feeling heartbroken yet resolute, Tang Xin kissed him, marking the end of her four years of unrequited love. Later, she reflected on their past and cried.