Sure, they're pretty, and sure, they can work, but they're not the best. Anime and pop-culture are only using them for the former; because Anime is japanese, so are katanas, that's justified, but the runoff of Anime is spilling into pop-culture leading people to believe that the katana is the best form of sword in the known universe. This is why I hate fads.
Opinions aside, the Katana is a gently curved blade, single-edged, which lacks a large crossguard, but does have some form of guard between the hilt and blade. It, like the european bastard sword, may be used in one OR two hands, and it was traditionally used by the Samurai.
Please, before you create a character for Role Playing, or buy a sword, consider your options, and open your mind to other swords.
"I'm not fond of katanas, I prefer a nice, simple longsword."
The katana came into use in the 1400's, before hand the Tachi was used, a longer sword used on horseback and worn in a different manner. Before that were the straight blades, Chokuto, from China. The katana is usually worn with the cutting edge (Ha) facing upwards, thrust through an Obi (belt). On rare occasions, The Katana was worn blade down (sometimes when armour was worn). It was usually the primary weapon of a warrior or Samurai, though in wars Yari (spear) were prefered due to the damage they inflicted on Armour, along with Maai (distancing).
In the beginning, before katana, were bronze, single-edged straight swords. These swords originated from China, and came to Japan through trading and conquest. From there, the blade was then made from a low-quality iron, with a slight curve, a side-effect of forging a single-edged blade. The early swords were simple, and ranged in sizes and shapes.
Most swords of this eary period are called tachi, and while the general use of a tachi was for battle on horseback, it saw little use with footsoldiers, who were sent into battle with spears or early naginata. Tachi is different from katana because they are different ways of carrying the blade. A katana and tachi blade are often very similar, but in tachi, the sword is worn blade down, usually tied or hung to a belt. In katana, the sword is held blade up, and is usually thrust into a belt, or in some cases tied to one.
Another misconception is the idea that anybody who has a katana is samurai. Samurai basically means, One who serves, and this fits them exactly. Samurai were warriors in feudal Japan that served a lord. It was a title that many people with swords either did not have, or could never get.
The katana was mainly a show of importance, and often displayed a person's rank or status. Peasants were not allowed to carry a blade over a certain length, and most carried none at all. A person of samurai rank or above could wear two swords, called daisho. Daisho consists of a long sword and a short sword. this also varied among the ranks. A wakizashi was a shorter sword, and often times, a low ranking samurai could only wear a wakizashi and a shorter sword, or knife. higher ranking samurai could wear a daito or wakizashi. This daito could either be katana or tachi.
Contrary to popular belief, the curved katana was not the only type of sword used in Japan. Much like in Europe's feudal age, swords were designed for the types of armor they went up against. European swords ranged from single edges baldes to double edged, but it is the double edged that gets all the publicity. Much like in Japan, the curved blade gets the most publicity. Why? In europe, heavy armor made from plates and links of metal required a sword that could take a beating, and thus it had two sharp edges. The point of a double-edged weapon also served to drive the point into weak spots in armor. The curved blades of Japan, however, were put up against armor that usually consisted of heavy silk or light leather that had strips of metal woven in. This was armor that could be cut easily, and thus the sweeping, slicing stroke of a curved sword was effective.
The big misconception between european swords and japanese swords are their cutting ability. Japanese swords will usually outperform european swords on the same level as far as cutting light things like clothing, mats, people, etc. However, european swords can take more of a beating and can usually hold their edges better.
Another myth is that the Japanese sword is superior to european swords. Like I have stated, this is not true. There have been accounts of a foot-soldier's katana cutting through a european foot-soldier's longsword. Now you have to think about geography. Japan, being a island, made obtaining the raw materials to construct a blade difficult and expensive to obtain. A complex method was usually used, in which iron rich sand was purified and folded into fairly carbon consistent steel. In Europe, iron was fairly easy to come by, and steel was often made. However, a common footsoldier would need to be outfitted cheaply. A european sword for a common soldier would be weak, and probably very poorly crafted, but they had no reason to be well-crafted. A softer sword would not break very easily, and most european swords were used as clubs with edges. However, in Japan, a footsoldier's sword would often be the same quiality as a general's sword because smiths could not afford to make swords cheaply and waste raw materials.
Another thing, katana could deflect bullets! Whoo! Everybody asks me that. Now, in fuedal Japan, guns were not very powerful, and could be deflected with a sword. However, chances are you would never get it right, and the bullet would would hit you instead of your blade. Another thing, the blades were often pretty thin, and depending on the temper of the steel, the sword would either bend, crack, or shatter. Now, the idea you get in movies that a person could defect multiple bullets back at the shooter is plain fantasy. The best you could probably do is mess up your blade, and waste time that could be used to get out of the line of fire. Now, that was back then. Even if you could travel fast enough to get a katana perfectly in line, if I shot you with a standard modern handgun, you would probably get shot. The sword would probably get pushed aside, or if your arms were strong enough, the blade would fail. No doubt about it. Japanese swords can cut through steel, as long as the steel is significantly softer than the sword steel, and even then, the sword would be messed up.
And you don't block a sword with the edge of a Japanese sword! The edges of Japanese blades are very hard and brittle, good for cutting, but another reason why they can't hold up to the same beating as european swords. Katana are softer on the back of the balde than on the edge. Parries would take place on the back, and even it would really be a parry, not a block.
2. A high-performance range of motorbikes made by Suzuki in the 1980s
3. An entirely different and unspeakably ugly range of motorbikes sold to gullible yanks since 1988 as Katanas, but known to the Free World as "Teapots" due to their bulbous appearance
2. In 1982, the fastest production bike in the world was the Suzuki GSX1100SZ Katana.
3. Seppo: "Hey man, I got me a 98 Katana 600... it's awesome."
Non-seppo: "No, what you have is a Teapot. It is less exciting than Bing Crosby and uglier than Mo Mowlam."