Let me comment now on the Japanese language. For those of you who don't know, "Arigato" (as in Domo Arigato Mr. Roboto) means "thank you". So every time I wanted to say thank you to someone, I had to sing the song in my head before speaking.
Also, the word for "yes" is "hi". I'm not talking just a casual "hi", the force in which they say this word shows that they must be using all of their stomach muscles. Try saying "hi" while flexing all of your muscles in a quick snap, almost like a judo chop. Try it, its actually pretty hilarious.
So people would know we speak English, but occasionally speak in Japanese throughout a conversation. Talking to a Japanese person felt like talking to a schizo constantly starting the conversation over. For example, "Hello, welcome to the hostel. What is your name?"
"Hi! Okay. Fill out this paper here."
(I hand back the filled out paper)
"Hi! Okay, your room is 202. Hi! Up the stairs here and enter this code on the door to get in to the level. Hi! The desk closes at 9:00."
"Okay, thank you."
Also, lets be honest, Koreans look shockingly similar to Japanese people. For the past six months our brains have been trained to respond in Korean when spoken to by an Asian. So, when spoken to in broken English, it was extremely instinctual to reply to the Japanese in a language they didn't understand.