Oomoto is a religion that is obsessed with Esperanto.
It was founded by an impoverished Japanese women who wrote an incoherent text about the corruption of the world. She named as her successor a bipolar man who wandered around East Asia trying to spread Esperanto in order to save the world.
Today Oomoto is building a temple in Mongolia, where people do not have enough food to live comfortably, in order to teach them Esperanto.