This post is dedicated to two girls. Actress Drew Barrymore and a normal girl in Japan with a similar flawless style.
Drew's current casual style is to almost always wear a short jacket, partly because it's flattering to her short stature, and a nice big scarf. She seems very attached to her purple
Sir Alistair Rai scarf.
She even carried her jacket and scarf style into her recent movie,
Music and Lyrics. Well, when you are your own producer, I guess you can wear whatever you want!

Another place this style popped up was Paris Fashion Week 07 in the Balenciaga collection.

Like the model on the far right, Drew also teamed her typical jacket style with stripes as you can see below.

So...on to the Japan part...
The girl below, spotted in Daikanyama, has used every cool little quirk previously mentioned - the short jacket, the scarf, the stripey shirt, the scarf - and it's a perfect outfit.

The splash of color created by the shoes and scarf is great. People shy away from yellow, but look at how cool it is if you do it right! And the bag completes the look perfectly.
Her bag was an excellent accessory as well. It has a similar style to the Dior lambskin bag.

Major points to you, Daikanyama Girl
Especially since you probably came up with it on your own, you didn't get tips from a professional stylist like Drew does. ::nods::