Take 1920 ~ 1940's common left chest pocket work shirt as the blueprint.
Improve the cut and silhouette and keep its classic design for a better fit.
Early shirts had no pockets. In the 19th century, with the progress of industrialization in western countries, a large number of different types of workers in different fields emerged. The shirts used to be underwear or canonicals can no longer meet the work needs of the working people. The functional design of the pocket appears on the left chest of the shirt (because most people are right-handed).
According to the different needs of workers of different types of work, various functional designs such as bag cover, double bag, and so on are gradually developed.
This kind of design detail, which existed only for work at the beginning, is no longer concerned about its practicability, but more about the sense of hierarchy brought by collocation. A hundred years ago, people thought that this has become a more classic design.