On her instagram, she also wrote a longer post about it and about the movie, so let me translate below: [may contain mistakes]
“The key frame illustration book has finally also arrived at my house! Brilliance full of gifts… Thank you so much! I want to bow my head to all the amazing key frames in the book… Actually I should tell myself to work hard as well~! It’s been roughly 2 years since the TV anime aired!
I am so very happy to be involved in such a well-beloved project. Thank you so much for your continuous support. It always gets to me.
We often are hurried by overseas fans writing “When is more news coming??”, but we’re all working hard on the movie behind the scenes! I just can’t show you the things I’m drawing now! I am giving my undivided attention to daily work, and food, in that order nowadays.
Since it’s all behind the scenes, there is nothing I will be able to announce before the official channels, but I will appreciate if you look out for me!
Now that the GP series has started, there’s too many things to look out for…”