The formal name of the temple is Shoshūzan Muen-ji Ekō-in (諸宗山 無縁寺 回向院), reflecting its founding principle of Pariṇāmanā, or the spreading of Amida Buddha's benevolence to all souls of all living creatures.

For this purpose he erected a monument called the Banninzuka (Mound of a Million Souls)[2] and held a great memorial service conducted by Jun'yo Jōjin (遵誉上人, Holy Priest Junyo) of Zōjō-ji.

This was the origin of the Ekō-in, which today continues to offer a resting place for any soul who did not leave relatives behind, including victims of natural disasters, prisoners, and animals.

The kanjin-zumō, a charity fund raising event permitted by the Tokugawa shogunate and the origin of the current professional sumo, was first held in the temple in September 1768.

[3] In 1909, the tournaments were moved into the original Ryōgoku Kokugikan, a modern arena in the temple precincts that had a capacity of 13,000 spectators and that was nicknamed as the Great Iron Umbrella.