I've heard aozora for blue sky many times, so it's true but not used as a substitute in every case. One of my favorite confusing words is charenji, or "challen

I've heard aozora for blue sky many times, so it's true but not used as a substitute in every case. One of my favorite confusing words is charenji, or "challenge", which essentially means "to try [doing something difficult]". So a Japanese tourist couple shows up at an American bungee jump and they tell the guys, "we want to challenge!" which sounds like a mistaken version of "we want _A_ challenge" in English. So the junior bungee jump guy looks over at his boss, and says, "hey...these two say they want a challenge..." not realizing they just want to try a normal bungee jump.