You can obtain the Soy Beans trait in Dungeon Village 2 for your city by Aged Soy Beans. Worth 3 points, Aged Soy Beans is the most points towards obtaining the Soy Beans trait.
The Soy Beans trait is a requirement for four titles, including Secret To Long Life, Stink Town and Healthy Town.
The exact contribution of points for each factor in the Soy Beans trait is detailed below.