According to the official website, an OVA of Astarotte no Omocha!
was announced to be released on September 7th.
According to the official website, the third volume of Yozakura Quartet: Hoshi no Umi
OVA was announced to be released on November 9th. It will be the final volume of the OVA series.
Sources: Amazon Japan
, Yozakura OVA official website
, Astarotte official website
Astarotte no Omocha! OVA