It's a Manga. If unsure look up the meaning in Wikipedia >.>
The story is like the name says, about a bartender.
"Genius Bartender, Ryu Sasakura makes the most incredible cocktails anyone has ever tasted. Seeking his "Glass of God", individuals from all different walks of life visit his bar. With both a compassionate ear and a godly drink, Ryu helps people with their problems." --- stolen taken from ANN