This movie was released in 1994 and stars Jean Reno as the leading character (the hitman) and also stars Gary Oldman as Stansfeild a corrupt DEA agent and a young Natalie Portman in her feature film debut.
Leon a stone cold killer and professional hit man is plodding along with his discrete,lonely and foul existence making no noise and keeping to himself and nurturing his plant which he calls his best friend. That is until he spots Mathilda a twelve year old girl who on there first meet is smoking a cigarette and sporting a black eye. Mathilda's abusive father and self absorbed mother have not noticed she has quit her school for troubled children and when her dad gets caught by the police for selling drugs, drug addict and dirty agent Stansfield (Gary Oldman) looses control during the raid and murders Mathilda's family one by one. Mathilda returns home and walks past her flat door realizing a raid is happening,she spots Leon who has been watching the raid go on and begs him to let her in and after thinking about it Leon makes a strained decision to let the crying girl in to his flat.

Mathilda now living with Leon soon realizes he is a cleaner,(hitman) and begs him to teach her the tricks of his trade which he does and in return Mathilda cleans the apartment,does the grocery shopping and even teaches the Hitman how to read. Taking a liking to Leon, Mathilda also tells him she loves him on a number of occasions to which she gets no response.
When Mathilda learns to shoot the first thing she does is get a bag of Leon's guns and goes after the dirty cop who has killed her family,blagging her way into the D.A office dressed as a delivery girl she is ambushed by stansfield in the bathroom where he tells her Leon has already killed the other cop she is after. Mathilda is saved from a dangerous situation when Leon after reading a note she had left goes and saves her killing two of Stansfields men in the process. Angry more of his men are dead Stansfield goes after Mathilda and Leon at there flat,in the battle that commences Leon and Stansfeild both die in a bomb blast as Mathilda escapes and goes to see Leon's boss who does his best to try and make Mathilda a hired Hitwomen not giving her the money Leon had given him to give her.

She runs back to her old school telling her story to a female teacher who takes pity and readmits her into the school,she walks out to a field nearby with Leons plant in hand and plants it the way she had told him he should,to give it roots.