[1] While the origins of the mihashira torii cannot be directly proven, it is sometimes thought to be linked to early Christianity in Japan.
The primary historical example of a mihashira torii is found in the records of Konoshima Shrine in Kyoto.
The text hints at a reference to Christianity in the construction of the torii, and says that the three pillars represent the heavens, the earth, and mankind.
The Konoshima torii stands in a pond with a pile of stones in the middle of the structure, supposedly the seat of a God.
[1] A private garden in Kyoto also exhibits a mihashira torii, built in a stream.