1. Goto: http://hitman.de/sniper/
2. Fill it out...
3. Check your email...
4. Goto: http://hitmansniper.com/redeem
5. Log in or register if you need to...
6. Enter the key...
In Japanese language, all you need to do is scroll to the middle and you will find a box, enter your email and confirm the confirmation email and moments later you will gt key.