Aja Winery is a store in Harvest Moon: Back to Nature.
The winery is managed by Duke and his wife Manna. The Aja Winery is named after their daughter who ran away from home years ago. To get to the winery, exit your farm through the front entrance (near your mailbox) and run past the Blacksmith. The Aja Winery is the next house on your left.
The winery is also the home of Duke and Manna. Manna will sell wine and juice from inside the home, and the wine is stored in the wine cellar. Finally, there is a small vineyard in the yard beside the house.
You can never buy anything from Duke, but you can see him in the vineyard or in the wine cellar from time to time. The important 'fall wine harvest' event happens here too, which is crucial to Cliff staying in Mineral Town.
Manna sells wine and juice from inside of their home from 10 in the morning until noon.
Fall Wine Event
During Fall of your first year, Duke will come to your home on Fall 14. He asks if you'd like to help him harvest grapes the following day. If you offer your help, he will ask that you bring a friend to help. Speak to Cliff the following morning before you're due to start and he'll offer to help you with the work.
After the event, Duke decides to hire Cliff on as a permanent winery employee. Cliff is so happy that he'll decide to stay in Mineral Town. Completing this event is the only way to get Cliff to stay in Mineral Town, otherwise he will move out in Winter.