So should I start speaking in Japanese? lol If I recall I got kicked for having a name in Japanese... speaking a different language hinders one person unable to 'comply' in a situation which would give you grounds to shoot them. This is highly unfair.
Example
P1: Hello, hands up.
P2: *puts up hands*
P1:座ってか死ぬ!(sit or die)
P2: I don't know what you said
P1: *shoots for none compliance*
^^ Not very fair as the second player doesn't have a chance. I find it not very 'RP' like if both parties can't participate.