夜勤病棟 (Yakin Byoutou; "Night Shift Nurses" in English) is an erotic visual novel series by Mink and their subdivisions "M no VIOLET" and "M ni AQUA". The brand also includes several erotic mahjong games, multiple hentai OVAs, a pachislo (slot machine) game and SM club.
森田和明 (Morita Kazuaki): Character Design, Genga
Yakin Jantou (2002), Yakin Byoutou Ni (2004), Yakin Byoutou San (2004), Nanase Ren (2005), Yakin Jantou Ni (2005), Kazama Mana (2006), Yakin Jantou Ichi Ni Fukkokuban+ (2008)
Yakin Byoutou Zero (2012)