So here's the tutorial!
It's full height( which I forgot to mention) is 25,6cm(10,07').
It doesn't take much time to build such weapon(toy).
Anyway, I hope you will enjoy(or already enjoyed) and tell me what you think, whether you didn't understand something or just have any questions.
Since I was a kid, I have learned how to make these kunais and shurikens, even scrolls, swords...
Here's a bigger photo I took afterwards: [link]
So I hope it helped.