According to the Dragon Age Comic Information booklet, Matra Milan
's manga "Omamori Himari
" was announced to get a TV anime adaptation. Matra Milan had been creating Adult manga since 1997 and Omamori Himari is his first non-adult manga series. The light novel adaptation of this manga has been published in Dragon Magazine since 2008.
Matra Milan acknowledged Studio Hibari
in the afterword of the manga volume 5, indicating the production studio to be Hibari.
Source: Scan of the booklet and the cover of volume 5