The Katana sword is a melee weapon in Dead Rising 2 and Dead Rising 2: Case West. They can be found in Shoal Nightclub after the twins Amber and Crystal are defeated. Two can be obtained by taking them immediately after the twins have been defeated. Like other psychopath weapons, both Katana Swords respawn at the Shoal Nightclub if they break.
In Dead Rising 2: Case West, the katana sword is a lot less-fancy looking and a lot less-durable than its DR2 counterpart. It can only be found in certain areas of the map, most commonly in the Living Quarters. This weapon can also be combined with a Sickle to create a Reaper.
The Katana is different from the Katana Sword in Dead Rising 2: Off the Record, the Katana can be combined to make the Reaper, the Katana Sword cannot.
It is affected by two books - both the Blades and Games magazines affect it.
The Katana Sword bears a slight resemblance to the Tenso from Onimusha 3: Demon Siege.
Despite being called a Katana, it doesn't have any design similarities to a real Katana (e.g. the weapons blade is not curved upward in just a single direction).
The name "Katana Sword" is actually redundant, as "katana" means "sword" in Japanese.
The reason why it is called the Katana Sword in DR2 is perhaps because the Ninja Pack DLC gives new move sets to "Swords"