Join Avenue is a new feature introduced within Pokémon Black 2 & White 2. It's a building located in between Route 4 and Nimbasa City and is empty at the beginning. Immediately after entering the building, the owner will stop and talk to you about how he would like to expand the place with your help.
In order to expand your Join Avenue, you will need to connect with other trainers through various connection capabilities such as; Wi-Fi, C-Gear, InfaRed and local Wireless. As soon as you encounter a trainer through one of these methods, they will automatically appear in your Join Avenue. However, in order for them to open up a shop, they somewhat have to get your permission. Go on ahead and talk to their avatar and they'll tell you about how they're interested in opening up a shop. Accept and the shop will be set up.
Additionally, there are various types of shops that can be opened up which are generated by the trainers "Trainer ID" and the game they used to connect with you. There are a total of 8 types of shops that can be opened in your Join Avenue and each of them sell different types of items. Here's the list:
- Beauty Shop
- Thrift Shop
Note: Once your store starts to get more popular, more and more trainers including Gymleaders will start to appear. Also, after beating the Elite Four, various fans will start to appear as well.