I happened to turn on the TV and saw a programme called "Why do students clean their classrooms at school?" Then I found out that it comes from a Buddhist story.
Suddhipanthaka was a disciple of the Buddha. He was known for being the most dim-witted of the Buddha's disciples, unable to understand the Buddha's teachings, and almost completely forgetting everything the Buddha said.
According to legend, one day the Buddha assigned him to sweep the ground. After a long time, Suddhipanthaka said "The ground is clean, but is my mind-ground clean?" Thereupon he attained enlightenment.
(
https://en.wikipedia.org/wiki/Suddhipanthaka)
This led to cleaning being considered a form of training in Buddhist temples, which was then passed on to the temple school (the private elementary school in the Edo period), and now students still clean their own classrooms in Japanese schools.
Knowing JoS, I know that the story of Suddhipanthaka is a spiritual story. Cleaning the room and environment is important for hygiene, but spiritual cleaning means cleaning the chakras and aura. Yet, Japanese temples only teach people to clean their rooms and houses.
By the way, physical and mental illnesses caused by Zen practice and meditation are called Zen illnesses in Japan. Symptoms of Zen illness include headache, nausea, chest pain, diarrhoea, constipation, cold, bloating, uncontrolled emotions, hallucinations and auditory hallucinations, which vary from person to person. Zen practitioners have suffered from Zen illness since ancient times, and the method of visualization and breathing was proposed by Zen Master Hakuin in the Edo period as a way of curing this Zen illness.(https://en.wikipedia.org/wiki/Hakuin_Ekaku)That seems like a breakthrough, but in fact it was already conveyed by the story of Suddhipanthaka.
I am concerned that I am giving it the wrong consideration...