currently i have the pleasure of living in Italy (Florence) the thing is that i am a poor poor student and money is an issue.
How would you name this shirt?
I would sit down with a pen and paper and think about all the masculine names I like. Then I'd jot down some of my favorites and go through a process of elimination to find the perfect name for that shirt. Or you could use a book of names like some people do when they're going to have kids.
I would "call" for it or describe it as denim jacket. It appears to branded by Levi's according to the red tap on the left breast pocket.
Although it appears to be a denim shirt, I believe it to be a very tightly fitted jean jacket by Levi's due to the horizontal chest seam.
I hope this helps.