How To Live on Earth (2008)

There are three people: an alien woman who comes up to an alien husband and a government's assassin wife who has to kill the alien woman. The wife is an undercover agent who is in charge of national top secrets. To her, her poet husband is like an alien. The husband has a key inside his head and the wife has a gun by her hand. Also the alien woman has purposeful love. Their mixed-up destiny does not just happen and the devil reveals his real shape and starts to kill people one by one.