Duke runs the AJ Winery with his wife Manna. In the Summer he harvests the grapes that grow on his property and then converts them into delicious wine. Duke is quite fond of drinking the items he produces.

Duke and Manna have a daugher named Aja, who the winery is named after. Aja and Duke had a quarrel some time ago and Aja moved out of Mineral Town. Duke, being stubborn, doesn't talk much about his missing daughter. Manna is still a little upset with Duke for the fight and wishes her daughter would return, but she becomes even more irritated with him when she finds out he's been drinking.