All the shops I tried didn´t have one in his favorite colour blue.
So I said I would make one myself and he agreed!
He chose this lovely fabric from my stash:
It may look blue in the pictures, but it is a gorgeous, rich, dark purple fabric with sweet owls, called "Eerie alley" by Robert Kaufman. For the lining I tried a laminated fabric from the Nicey Jane range by Heather Bailey. It is very easy to sew with. Just take care with pins, because they leave permanent holes.
For the inside of a pencil case, oilcloth is stronger and easier to clean than cotton.
Here´s the result: