The building to the right of the main hall is the Asakusa Jinja, a Shinto shrine dedicated to the three legendary founders the Sanja of Sensoji.
Sanja of Sensoji was founded by one person. 
mnli hypothesis: Sanja of Sensoji was founded by one person.  premise: The building to the right of the main hall is the Asakusa Jinja, a Shinto shrine dedicated to the three legendary founders the Sanja of Sensoji.