So I've recently gotten really interested in Japanese history around the Edo and Meiji periods, especially in the titles of the Imperial Court, family and the Tokugawa clan. Now there are numerous special titles, ones for retired Emperors, retired Shoguns, Wives of the Shoguns and Emperors and other things of that nature but I can't seem to find if the heir of the Shogunate had an official title. So did they and if so what was the title?