Seven years ago, Cai Shengtong and Wu Shunli were the couple that everyone envied on the campus of A University. However, they broke up hastily due to a misunderstanding that involved family pressure and youthful stubbornness, and they became mutual regrets. Seven years later, Cai Shengtong is already a well-known architect in the industry, independent and sober, burying the past deep in his heart; Wu Shunli has become a popular investor in the capital circle, calm and restrained, with lingering warmth in his eyes. A bid for a landmark project suddenly reunited the two as Party A and Party B. The tit-for-tat confrontation at work has opened up old scars. The backseats of bicycles on campus and the side-by-side figures in the library form a strong contrast with the neon lights of the city at night and the offense and defense on the negotiation table. He pressed forward step by step, trying to make up for the past debt; she built a wall in her heart, but inadvertently revealed her softness. When the dusty misunderstandings are peeled away layer by layer, can the two people who have lost their youthfulness hold each other's hands again in the echo of time?