Talking about japanese idioms, a friend told me that 引き籠もり means "bat". That sounded strange to me, because I thought that "bat" translates as バット, thinking of the old anime "ogon batto". But then I searched for more information and found out that "bat" as animal translates to コウモリ, which might have some similarities. I still think that it's purely incidental. コウモリ has a different sound and is written in katakana, and even if written in kanji it's a completely different word. So, I still think that his information was wrong. Are the 2 words somehow related?
by ponyservice