Blueberrys doesn't naturally grow in Japan and are therefore kind of rare and expensive to get hold of.
That's why these KitKat Blueberrys are very popular.
They are based on regular milk chocolate and have a faint blueberry scent.
They taste somewhat like blueberrys, but not quite.
Maybey it's because I'm spoiled with naturally grown blueberrys ;)
Still, they are pretty tasty.