Not certain of the other components and whether or not koji is the only leavening ingredient used. The following quote (and pic) is from the baker's blog: http://franccastella.com/oheso-cafe/ 
In Oheso Cafe try to provide full food naturally grown, traditional and of course 100% organic. Our menu is focused on bread and bread products, our bread is cooked with natural enzymes from rice Koji mold exactly, used in Japan to make miso, sake, Amasake and numerous products of the fermentation of the fungus soybeans, rice.
This is a beautiful looking place.....
(the bread looks fantastic too)
Photo of bread at Oheso Cafe, by http://franccastella.com/oheso-cafe/