Bocchi no Boku ni Kyousei Kanojo ga Yattekita

On my 24th birthday, I came home to find a woman who wanted to be my girlfriend! As a "loner" since junior high school, I was confused by all this. But the truth is she is my mother's junior at work, and my mother asked her to!? A pseudo-romance between two people with the same interests has begun! (Source: Houbunsha, translated)