Exorsister Maria

From MangaHelpers: Very rarely, rifts in dimensions occur and creatures that people refer to as demons infiltrate our world. Koichiro and Maria was a young couple who unfortunately was targeted by one of these demons. Koichiro was cursed with a spell called Midnight Supper and turned into a mouse that can only turn back into a human for three minutes at midnight. The only way to break the curse is to find and kill 99 demons. With the help of Maria, the love of his life, the pair fights together to regain Koichiro’s human body back.