Ginko employs himself as a Mushi master (mushishi), traveling from place to place to research Mushi and aid people suffering from problems caused by them.
Ginko is a rare person who attracts mushi. This inspires his peripatetic lifestyle; staying in one place too long will gather a potentially dangerous amount of mushi. He also smokes constantly in order to keep mushi away.
In terms of personality, Ginko is rather laid back, but can be very serious when it comes to protecting people from mushi. He also often stresses that the mushi are not evil, but they merely exist as a part of the nature and try to survive like every other living being.