Jaejoong is going to open a coffee shop named "Coffee Cojjee" which is located in CheongDam-Dong.
https://twitter.com/hissinger/status/255954981620961281/photo/1/large The picture uploader said his friend is a barista in it, so he visited here. As you see the picture, the coffee shop logo is a J-shaped coffee cup, there are two j's in the coffee shop name "coffee cojjee" and the telephone number ends with '0126' which is Jaejoong's birthday. So...I think we can believe this info?!