I guess it comes from Yoga or Buddhism..it consists of 3 words, Dan+Sha+Ri.
Dan means cutting out, Sha means throwing away and Ri means leaving..it is kind of difficult to describe these words in English, as it doesn't have the exact same meanings.
In short, they recommend the simplification.
Nowadays we carry too much stuff and stress..so it is getting popular in Japan to throw away what you don't really need in order to have a simpler life.
It might sound like detox.
Today we introduced it to CRIB QUILT. It would be a good timing of looking at yourself again, to see your real surroundings and also a relationship between you and your belongings!