The haori is a lightweight silk jacket used to help keep the kimono clean and dry.
They are meant to be worn open. It's usually taken off and folded up before one enters the place they are visiting.
The haori can also be of different lengths, the long ones being for dressy wear, the medium-length ones for ordinary wear, and the shortest ones for wearing at home.
Fatemi sapere se ne comprate qualcuno, voglio vederli!