What are the bags used to contain katana/swords called?

Question:

for example as seen in http://wall.alphacoders.com/big.php?i=57578
I've seen it used in anime a lot, like in Ga Rei Zero and Inu Yasha. They're like fabric bag things with string tied around them, usually used to contain/wrap swords. Do they have a name or are they just called sword bags or something?

Answer:

It depends on what type of swards are contained.

There are several type of Japanese swards,
If it's 竹刀　"Shinai", Bamboo sword for Kendo practice, the bag would be called "Shinai Bukuro".
If it's 刀, "Katana", real Samurai sword, the bag is called "Katana Bukuro".
If it's 木刀, "Boku Tou",wooden sword for practice or self defense, the bag is called "Bokutou Bukuro".
If it's 太刀, "Tachi", old style battle sword, the bag is called "Tachi Bukuro".

"Fukuro" or "Bukuro" mean "bag".
Mostlikely, these high scool students have Shinai, Bamboo swords, it would be called "Shinai Bukuro". If it's samurai warriors, like in Inu Yasha, It's called Katana Bukuro.