A soreisha is usually a small shrine dedicated to the ancestral spirits of parishioners who have received a shinto rather than buddhist funeral.
Until 1868 shinto funerals were extremely rare, and only really came into existence with the separation of the buddhas and kamis in 1868.
Soresha were usually small and located in the grounds of the local shrines, and sometimes in private homes.
The daimyo of Tsuwano, however, decreed in 1868 that all of his subjects would receive shinto funerals.
From 1886 to 1945, soreisha became illegal within the grounds of regular shrines as they were deemed private and shrines were supposed to be public. Possibly this one in Tsuwano did not as everybody had to have shinto funerals, therefore the soresiha was public.
The daimyo of Tsuwano, and several other scholars of National Learning from Tsuwano were instrumental in creating the national policy of shinbutsu bunri as well as the persecution of buddhism. Anti-christian thought was also strong which is probably why "hidden christians" were sent here for "re-education"