
Quick answer — Enterbrain worked on Amagami SS+ plus (Original Creator), Amagami SS (Original Creator), Amagami SS OVA (Original Creator) and 2 more anime.
Enterbrain worked on Amagami SS+ plus (Original Creator), Amagami SS (Original Creator), Amagami SS OVA (Original Creator), Amagami SS: Sister (Original Creator), Kimikiss (Original Creator).