Games like Niflheim Academy

If you finished Niflheim Academy, the closest matches are Temirana: The Lucky Princess and the Tragic Knights, Amnesia, Shinsouban Mahoutsukai to Goshujin-sama: Wizard and The Master, Diabolik Lovers: Haunted Dark Bridal and Puss in Combat Boots. All 6 share its visual novel genre and are ranked by how closely their themes and modes overlap.