As I hear it told, Story of Seasons is made by Marvelous the same people who made Harvest Moon. Harvest Moon was localized by Natsume until Marvelous decided to switch to letting XSEED localize the Harvest Moon games. However, because Natsume originally localized Harvest Moon, they owned the name "Harvest Moon", so XSEED had to change the name to something else. So they picked "Story of Seasons".