Slipping in under the radar comes the hilarious one-episode OVA Yurumates ゆるめいつ, based on a 4-koma comic strip by saxyun.
The simple Flash+2D animation is funny enough, but the script and the seiyuus really make this a great little show. Hidamari Sketch with a drier wit.
Main character Yurume is played by seiyuu/singer Momoi Halko (Ai in Final Fantasy Unlimited, Komugi in Nurse Witch Komugi, Chika in Ai yori Aoshi, Utamaru in Da Capo, San in Seto no Hanayome). Momoi-san also wrote and performed the OP and ED:
Yurume comes to Tokyo to attend a cram school so she can get into college. She moves into a run-down little apartment house where the other three are already living.
The first tenant she meets, through a hole in the wall of her closet, is Sae, played by Kuwatani Natsuko (Yue in Negima, Suiseiseki in Rozen Maiden, Alph in Nanoha, Asakura in Suzumiya Haruhi, Yaya in Strawberry Panic):
The show makes its 4-koma origins completely obvious, dividing its 35 minutes into several brief sketches. The four stars drink together, cadge food off each other, huddle around the kotatsu in the winter, etc. etc.
Matsuki Miyu (Akane in Final Approach, Choppy in Precure Splash Star, Angulas in Simoun, Shion in Otoboku, Yoshinoya-sensei in Hidamari Sketch) is particularly funny as blonde, pig-tailed Kumi, who seems gentle, but drinks as much as anyone and can whip out a harisen to whack people with:
The male member of the quartet is Matsuyoshi, played by Satoshi Hino (Yuuji in Shakugan no Shana, Saitou in Zero no Tsukaima, Sai in naruto Shippuuden, Sanada in KimiKiss, Yuuri in Tayutama). He is put-upon, but not weak, and gets to spend lots of drinking time with the girls:
The director is an unknown called Tsukimizato Tomohiro 月見里智弘. The animation studio is indeprox, and the producers Takeshobo publishing. DVD released 24 April.
Give the show a look. I found it hilarious.