Alright, I was a bit confused about this release not being familiar with the source, but here is the deal. This is going to be a pair of “mid-length” movies (~40 minutes each) that adapt the Yuru Yuri spinoff manga Oomuro-ke.

• “Oomuro-ke: dear sisters” is the first to be released tomorrow (Feb. 2) in Japan.
• “Oomuro-ke: dear friends” is the second to be released on June 21st in Japan.

This particular visual is for the second of these two “movies” as is the newly released PV you can see here. If you want, this is the PV for the first installment.

Hope that helps people that were confused like I was! For completeness sake, the AniList synopsis of the source manga is simply:

A spin-off of the Yuru Yuri series featuring Sakurako and her sisters.