Katana and wakizashi

 and (samurai swords or Japanese swords) are one of the many forms of swords and daggers. But behind stats, katana and wakizashi are very desirable for their appearance as part of a roleplaying outfit.

They are often used by 7 agents.

List of katana and wakizashi
There are six models of katana (one and two-hand swords) and one model of wakizashi (dagger). Some swords represent wooden katana.

One-hand sword. Model I
These are curved ones.
 * Ginn-Su Sword - BoE, drop (Uldaman)
 * Rune Sword - BoE, word drop
 * Scourgebane's Slicer - BoP, Ice Delivery
 * Silent Fang - BoP, drop (Scholomance)
 * Sword of the Falling Sky - BoP, Saving Foreman Oslow
 * Wicked Mithril Blade - BoE, crafted by blacksmiths

One-hand sword. Model II
These are straight ones.
 * Assassination Blade - BoE, world drop
 * Doomforged Straightedge - BoE, world drop
 * Hanzo Sword - BoE, world drop
 * Joonho's Mercy - BoE, drop (General Fangferror (rare))
 * Reforged Blade of Heroes - BoE, crafted by blacksmiths from Broken Blade of Heroes
 * Skystrider Katana - BoE, Outland world drop
 * Taurajo Butcher's Blade - BoP, The Butcher of Taurajo

One-hand sword. Model III

 * Misery's End (sword) (wooden) - BoP, Feegly the Exiled (quest)

Two-hand sword. Model I

 * Boneslasher - BoE, drop (Razorfen Downs)
 * Dacian Falx - vendor
 * Duskbringer† - BoE, dropped in Shadowfang Keep (Classic)
 * Frost Tiger Blade - BoE, crafted by blacksmiths
 * Headstriker Sword - BoE, world drop
 * Ta'Kierthan Songblade - BoE, drop (Lord Darkscythe (rare))

Two-hand sword. Model II

 * Archaic Defender - BoE, world drop
 * Blade of Hanna - BoE, drop (classic 40-men raids)
 * Typhoon (weapon)† - BoP, dropped by Azuregos

Two-hand sword. Model III

 * Helboar Carving Blade - BoP, Testing the Antidote
 * Mo'grosh Toothpick†(wooden) - BoE, dropped by Mo'grosh Ogre
 * Shin Blade - BoE, drop (classic 40-men raids)

Dagger

 * Assassin's Blade† - BoE, dropped in Shadowfang Keep (Classic)
 * Dreadblade - BoE, world drop
 * Permafrost Dagger - BoE, Outland world drop
 * Skilled Fighting Blade† - BoP, Jail Break!
 * Sliverblade‡ - BoE, dropped in the original Scarlet Monastery instances
 * Stealthblade - BoE, drop (Sunken Temple)
 * Survivor's Blade - BoP, Bael'dun Rescue
 * Talongrip Dagger - BoP, The Queen and Her Court

† - No longer obtainable after Cataclysm

‡ - No longer obtainable after Mists of Pandaria

Trivia

 * Katana (and wakizashi) is (are) very suited to ninja or bandit transformation form (Flip Out buff from Savory Deviate Delight)