Original: It occupies the site of the former Kan'ei-ji, a temple closely associated with the Tokugawa shoguns, who had built the temple to guard Edo Castle against the north-east, then considered an unlucky direction.
Simplified: It stands in the site of an old Kan'eiji, a temple very related with the Tokugawa shoguns, who had built the temple to guard Edo Castle against the Northeast.