According to e-hon, an OVA of Sano Tae's manga "Morita-san wa Mukuchi" was announced to be released on January 26th 2011. It will be bundled with the manga volume 3 special edition.
Cover of Morita-san wa Mukuchi manga vol.1
Morita Mayu is a high school girl. She is extremely reticent and her silence and habit of looking at people's eyes straightly sometimes cause misunderstanding. But she lives a happy school life with her classmates.