Inokashira Benzaiten was said to have been established during the Tenkei Era (938-946) by Minamoto-no-Tsunemoto, the patriarch of Kanto Genji who enshrined the Benzaiten Goddess Statue crafted by Dengyo Daishi in Enryaku-8 (789). Later, Minamoto-no-Yoritomo was said to have built the shrine pavilions to pray for the peace and quiet of the eastern part of country in Kennkyuu 8 (1197). As the story goes, victory prayers were performed when Nitta Yoshisada fought against Houjou, Kamakura in Shoukei 2 (1333).

In the Edo Era, Tokugawa Ieyasu modernized the water supply when he entered Edo. Water was channeled into Inokashiraike-Pond, the selected water source, from Kandagawa-River.

They say that Ieyasu visited this area several times in Keichou 11 (1606) to make tea with the water from Inokashira Pond. His handheld tea mill is still kept in Bentendou-Hall.

This area was used as a hawk-hunting ground in the age of Iemitsu, the 3rd General. It took the name “Inokashira” when Iemitsu visited in Kanei 6 (1629) to carve the characters "Inokashira" onto a magnolia tree at the edge of lake with his short sword. The lake (Well: “I-”) was important because it supplied drinkable water to the people of Edo (Head: Kashira).