Shirou Fujieda is the owner and sommelier of the wine bar "Monopole," the mentor of Miyabi, and a trusted counselor for Shizuku. While quick remind Shizuku and his friends of their ever-growing tabs, he is very generous and often takes out fine wines to treat friends and provides samples to help Shizuku whenever he needs it. In his younger days, he studied wine in France and used to be a member of the student protest and communist movements.

(Source: Wikipedia, edited)