The production team for the Yuru Yuri spin-off anime Oomuro-ke has revealed four new voice cast members and character designs joining the two 40-minute anime films. The films are titled Oomuro-ke: Dear Sisters and Oomuro-ke: Dear Friends and will both premiere in Japan sometime in 2024.
The additional cast members include Reo Kurachi as Kokoro Ogawa, Ayasa Itou as Mirai Soma, Aoi Koga as Misaki, and Suzuko Mimori as Himawari Furutani (who returns from the main series).
They join a main cast that includes Emiri Katou as Sakurako Oomuro, Chiwa Saitou as Nadeshiko Oomuro, and Rina Hidaka as Hanako Oomuro.
Oomuro-ke: Dear Sisters and Oomuro-ke: Dear Friends will be directed and storyboarded by Naoyuki Tatsuwa (Nisekoi director) with Masahiro Yokotani (Re: Zero) as scriptwriter and series screenwriter, Ueta Kazuyuki (Love Flops) as character designer, and Yuusuke Shirato (In the Heart of Kunoichi Tsubaki) as music composer. Passione and Studio Lings are handling the animation production for the two films.
Namori‘s Oomuro-ke manga was first launched on July 2, 2012 and has released six tankoubon volumes as of December 2022. The manga is published by Ichijinsha and currently serialized on Yurihime@pixiv. It follows the daily lives of Sakurako Oomuro and her sisters.

Sakurako was first introduced in the main YuruYuri manga series (also by Namori), which began on June 18, 2008 and inspired multiple anime series and OVAs.
Source: Oomuro-ke Official Anime Website