It's the Kid's Prize medal. You can earn one when you get around 10 attempts that are all 200-300th of a second behind Bronze.
You don't receive nothing if you have completed the licenze with all Kid's Prize.
The Leaf Significate: Japanese Symbol for Beginner. A yellow and green shield symbol, called a Shoshinsha Mark. Must be displayed by drivers in Japan for one year after they receive their drivers licence.
