Apparently this is a music school that is very difficult to enter based on the google translate. I seriously thought this is one of those north Korean schools in Japan.
For an European... this looks like some futuristic, medieval communistic-northkorean school (no offense meant). It is just very weird. The music, the stiffness, the whole ceremonial character of this Video and the creppy happy choir music in the background with all the fake smiles and strictly bound Pony tails and breads... very weird school