A young salaryman finds a teenage girl sitting under a lamp post on his way home. She offers to sleep with him in exchange for a place to stay. He turns her down, but gives her a place to stay anyway. Their strange life together begins...
I'm not sure how to answer that. 
"A teenage girl"?
Was ist das denn für eine Frage?
No sé bien cómo responder a eso.
Digamos que solo una adolescente.
No sé bien cómo responder a eso.
Digamos que una adolescente normal.
Ça se voit, non ? Une lycéenne.
Non so bene cosa rispondere... una liceale?
Não sei que resposta dar... 
"Uma menina"?
Даже не знаю, что сказать.
«Школьница», наверное?