This Hachiman-Gū's origins are very similar to those of the Shibuya Hikawa Jinja. and like it(s Shibuya counterpart it is one of the Eight Edo Hachiman-Gū. In 1062, following the precedent set by Yamato Takeru. Minamoto Yoshiie, otherwise known as Hachimantarō, set up a shrine in the area to celebrate his triumphal return from the Ōshū War. He dedicated his armour and sword at the shrine and designated it as the guardian shrine of the Northeast.
In 1641 part of the foothills on which the shrine stood were levelled to allow construction of a retreat for the shrine guard. During this work a cavity containing a gilt bronze carving of a kami was discovered and the shrine was thereafter known as Ana hachiman-Gū (Ana,穴, means cavity). In the same year a private secretary to the Bakufu, Ōhashi Ryūkei (大橋龍慶), donated a large amount of land to the shrine and an imposing new main hall was built.
At about the same time certain auspicious omens, including light emanating from a sacred pine tree in the shrine grounds, were observed. These came to the attention of the third Tokugawa Shōgun, Iemitsu; he formally declared the shrine to be the comprehensive spiritual guardian for the region to the north of the castle and authorised maintenance and repair work to be carried out.
(Note: numbers in parentheses after kami names
Jingūkōgō (kojki) 神功皇后
From Merged Shrines
Wakamiya Hachiman-Gū 若宮八幡宮
Himuro Myōjin 氷室明神
Kasuga Myōjin 春日明神
Koyasu Myōjin 子安明神
Itsukushima Jinja 厳島神社
In 1648 the shrine's parish (ujichi) was defined as 36 neighborhoods in what was then Uchigome, now part of Shinjuku. The following year the main hall was rebuilt and this was followed by the construction of several new buildings, some quite extravagant, so many in fact that on their completion the 8,8002 m+ shrine grounds were described as closely packed (櫛比, shippi ) and with continuing Tokugawa patronage the shrine soon became one of the most important in Edo. In 1703 a splendid new main hall was built, only to be burnt down in 1854. By this time the Bakufu was facing many problems and with the country in the grip of high inflation the best that could be done was the cobbling together of a temporary main hall. It was not until the beginning of the Showa Period (1926) that a new one, modeled on traditional designs, was opened amid much fanfare. Almost needless to say this was destroyed during the early 1945 fire bombings. A temporary structure was again erected, and in 1989 work on a complete reconstruction was started. It was essentially finished by 1998.
Three minutes on foot from Waseda Station. There is a lot to see in this shrine, and there is a small, manicured park in its grounds. One of its most interesting, and least garish points, is the Jimmu Tennō yōhai-jo (神武天皇遥拝所), literally the "place where Emperor Jimmu (the legendary first Emperor) can be worshipped from afar". The site points to the southwest to Kashigahara-Gū in Nara, which is said to be built on the spot where Emperor Jimmu ascended to the throne in 660 BC. While not quite as old as Emperor Jimmu the pair of komainu on the site, dating to 1755, are venerable in their own right..