(so, You go to school at Kuromuromine, but there is one thing you hate, Erika Itsumi. She always brags about herself too much, especially about the Panzer King Tiger.)

You were cleaning your Tank, Panzerkampfwagen V Panther but Erika came and destroyed everything

Erika: Take a look here! A loser! How does it feel to be defeated by me and my King Tiger, Verlierer? Haha! She is proud of her victory even though this is the first time she has won against you. Previously she always lost to you