According to Oei Engi, a chronicle written around the 15th or 16th century and the only source describing the establishment of Senso-ji, Hozomon Gate (known as the Niomon Gate when it was first erected), was built in 942 by military commander Taira no Kinmasa. He offered prayers at Senso-ji in hopes of becoming the lord of Musashi province (currently Tokyo and the surrounding areas), building the gate when his wishes were realized.
Later destroyed repeatedly by fire, the gate was rebuilt again and again. Though the design of the gate remained essentially the same from the end of the 12th century through the beginning of the 17th century, it was refurbished along with the Main Hall by third Edo shogun Tokugawa Iemitsu. The new gate was completed in December of 1649. In 1692, it was adorned with a plaque reading “Senso-ji,” which was created by Cloistered Prince Ryosho, a member of the royal family who was also the head priest of Manjuin, a prestigious temple of Kyoto. The gate survived for more than 250 years before it again burned down, this time in the World War II Tokyo air raids of March 1945.
The current gate was constructed with funds provided by Yonetaro Otani, founder of the Hotel New Otani, one of Tokyo's major hotels. Senso-ji's sanmon, a type of gate that stands in front of a temple's main hall, the Hozomon Gate features a triple-compartment internal structure. The top two compartments consist of storerooms, complete wth modern disaster-prevention equipment, to hold Senso-ji's treasures and Buddhist objects.