Start with the idea behind the place. In Edo-period belief, the northeast was the direction of the demon gate, the quarter from which misfortune was thought to arrive. Edo Castle's northeast corner needed protection, and the monk Tenkai, later honored as Jigen Daishi, advised the shogunate to build a temple there. The main residence of the temple was completed in 1625. The name carries its own date stamp. The temple received its imperial title from the era name of its founding years, Kan'ei, which is where the name Kan'eiji comes from. The founder, in the formal sense, was the third Tokugawa shogun, Tokugawa Iemitsu, while Tenkai served as the guiding monk behind it. And the plan was ambitious. Just as Mount Hiei guarded the old capital of Kyoto, Kan'eiji's hill was meant to protect the new capital of the shoguns. The hill and the temple together were a statement about where power now sat.