Boku no Gakkou no Ansatsu-bu

Having 157cm in height, for Fukasaku Reiji the fact of being 1cm shorter from an average girl in his age was a serious matter. Yet another problem arise when he witnesses the beatiful girl -Mitajima Yukari who attends the same school as him murdering a person. He later learns she is a part of [assasination department] which specializes in obliterating particular people in society. Reiji after falling in love with her decides to join up the organization. The story of puberty, love and conflict of a boy who step into the world of guns begins.

(Source: Jcafe24)