- Female protagonist: Lin Wanxing (graduate student in the Department of Modern History + inheritor of the intangible cultural heritage Su embroidery), calm, tough, thoughtful, with modern knowledge reserves (historical trends, basic first aid, business thinking) and Su embroidery skills. After traveling through time, she became the daughter of a down-and-out industrialist in Shanghai. Her family was framed and on the verge of bankruptcy, and her relatives were restrained.
- Male protagonist: Shen Yanzhi (the leader of the secret forces in Shanghai + underground anti-Japanese worker), who appears to be a suave president of the Concession Chamber of Commerce, but in fact is ambitious and decisive, secretly protecting the country, collecting intelligence, and carrying a blood feud.
- Travel background: Shanghai in 1935, the concession and the Chinese border coexisted, the shadow of war was shrouded, various forces were intertwined (Japanese army, Kuomintang, underground party, gangs), and glitz and crisis were intertwined.
- Core image: Cold plum - the heroine is like a winter plum, sticking to her heart and blooming with tenacity in troubled times; deep love - two-way protection in troubled times, the righteousness of family and country intertwined with the love of her children.
