Studio DEEN is an anime production studio that has produced adaptations of several 07th Expansion works.
- Higurashi When They Cry (adapts the Question Arcs, Meakashi-hen and Tsumihoroboshi-hen).
- Higurashi When They Cry Kai (includes an exclusive arc and adapts Minagoroshi-hen and Matsuribayashi-hen).
- Nekogoroshi-hen (OVA adapted from a light novel).
- Higurashi When They Cry Rei (OVA series adapted from the namesake VN).
- Higurashi no Naku Koro ni Kira (OVA series with original content).
- Higurashi no Naku Koro ni Kaku: Outbreak (OVA adapted from a short story included with Higurashi Daybreak).