Who is Subaru wife?

Before the battle with the Hakugei, Rem also proposed to become Subaru’s second wife and after the battle, she even went as far as to fake her death to force a confession out of him.

Does REM fall in love with Subaru?

After initially starting out on a bad foot, Rem eventually comes to fall for Subaru after he ends up emotionally and physically saving her during the events of the second arc, where afterwards she began devoting herself to him.