Kaminarimon gate, built by military commander Taira no Kinmasa in 942, was erected in the present location during the Kamakura period (1192-1333). At that time, statues of Fujin (wind god) and Raijin (thunder god) came to rest at either side of the gate.
People initially offered prayers to these two statues for the protection of the temple against natural disasters including typhoons, floods and fire. Over time, they became the subject of prayers for the benefit of the people, such as for a bountiful harvest and for peace in the world.
The gate was burned down in a massive fire in December 1865. After a period of 95 years, it was finally reconstructed by Konosuke Matsushita, founder of Matsushita Electric, the electronics company known for its Panasonic brand. The bold, dignified gate is known around Japan not only as a symbol of Senso-ji but of the whole of Asakusa.
Nitenmon Gate was originally erected in 1618 as the gate of Tosho-gu Shrine, once located inside the Senso-ji complex. Known also as Yadaijinmon Gate, it was dedicated to Japan's ancient Shinto gods. Tosho-gu Shrine was destroyed by fire in 1642, and this gate, along with the stone bridge located in front of Yogodo, were the only structures to survive.
Around the latter half of 19th century, the Meiji government had a policy of separating Shintoism and Buddhism. The statues of Zochoten and Jikokuten, previously owned by Tsurugaoka Hachiman-gu Shrine (a famous Shinto shrine of the Kamakura area) were moved to the Buddhist Senso-ji. The gate was re-named “Nitenmon Gate” in line with Buddhist terminology. Unfortunately the original statues were decimated during World War II. The two statues now guarding the gate came from Genyuin Hall (the gravesite of Tokugwa Ietsuna, the fourth Edo shogun) of Kanei-ji, the family temple of the Tokugawas at Ueno Park, Tokyo.
The gate has also been named an Important Cultural Property by the national government. The plaque on the gate that reads “Nitenmon” was created by Sanetomi Sanjo, a 19th century aristocrat and politician.