It all happend so quickly! I have now idea how this challenges developed but the core idea of it came from @politikundliebe on twitter. A list with the participants can be found in this (German) blogpost.
The only think you have to do to participate is watching at least 8 Japanes movies in January and talk about them on twitter, letterboxd or anywhere else by using the hashtag #Japanuary.
A few more for backup. 😁