Shen Yichen inherits an old house and makes a living collecting rent, having put his dream of becoming a comic artist on hold and grown accustomed to avoiding his own aspirations. After Jiang Miaomiao, Ye Xiaotang, and Gu Anran move into Apartment 404, four young people with very different personalities begin living together. Each carries their own worries and struggles, and while their life together brings disagreements and adjustments, it also offers understanding and companionship. Through everyday incidents, big and small, and countless heartfelt conversations, they gradually ease one another's loneliness. In the end, Shen Yichen gathers the courage to finish creating his comic. This lighthearted comedy follows the four roommates through their daily lives, telling the story of lonely people finding companionship in one another and learning to live bravely.