The show's soundtrack
From The Lost Media Wiki
While I couldn't find the rest of the Japanese soundtrack. On January 18th, 2020 Youtube user " Dougurasufilm" just uploaded the entire soundtrack to the series on Google Drive. Here's the Youtube video that has a link to the soundtrack in the description. https://www.youtube.com/watch?v=Z7vqhDnRzYY
Here's the Google Drive Link. https://drive.google.com/file/d/1wWX9_XPANhZXX9LAEnphcGm8FQBM5ZwP/view