Mariano Que began his career as a regular employee at a Manila drugstore during the prewar period. As a diligent employee, he learnt to appreciate his work and the significance it plays in Filipinos' daily lives. Then came the war, which took everything and destroyed everything in the city's busy streets. Mariano's former workplace, a drugstore, was also severely damaged, leaving him jobless. When the war ended, everything became scarce, even medicine. Mariano, being knowledgeable about medical prescriptions, realized that this period could be a good opportunity for him to help others and also, improve his finances. He subsequently began selling sulfa medicines, such as sulfathiazole tablets, for P100 in capital. He sold it in the city's most impoverished streets, where medicine lacked resources. And, because he was in the retail sector, he quickly sold out of everything he had. He used to sell these items on the streets, but after he had enough money, he acquired a push cart, or "kariton," and began selling even more medical products. By the formal end of the war, in 1945, Mariano had gained enough capital to put up a physical store, which he named Mercury Drug. The Roman god Mercury carried the caduceus symbol, which was largely associated with the medical profession