Eh, eh, I was in Japan from August 3rd to August 16. In fact, you need one day to go back there - 12 hours of direct flight, and more than one day to go there (7 time zones from Paris).
Japan is great, and it is very very different from any European country you can know of. I'm sure it is also very different from any other Asian country too... It is hyper-modern (sometimes extremely), and at the same time it retains a very particular culture and traditions.
For example... when you go to the toilets in Ryokans, or even in some museums, you must use specific slippers, because toilets are considered as a dirty room.
But Japan is much more than that:
You maybe have heard of CosPlay or Gothic Lolita girls. You will find a LOT of them in Japan, and not only in Tokyo Harajuku.
Here you will encounter people going to work in strict costume, people in kimonos,
(or even more traditional than that...)
young women wearing ultra-short skirts,
young boys and girls in school clothes,
and others in the Japanese version of Punk attire (which is not punk)
Here they seem to all live in harmony, as shrines can coexist with giant neon buildings.