- "A notorious blade passed down through generations of the Rodrigues family. Sam had it modified into a high-frequency blade, enhancing the already astonishing properties of the original metal and giving it an ominous crimson glow. An explosive charge housed in the scabbard enables a lightning-quick draw."
- ―HF Murasama weapons description in Metal Gear Rising: Revengeance
Jetstream Sam's signature blade replaces Raiden's original HF blade after it is destroyed by Steven Armstrong. It is available in the final boss battle, and is unlocked for normal use after beating the game once, costing 10,000 BP. It lacks its distinctive sheath, instead using Raiden's default one, and has the same moves and upgrade options as the regular HF Blade.
The Murasama is extremely powerful when fully upgraded and has superior reach to the HF Blade, making it the strongest weapon in the game in terms of raw damage, though the Fox Blade is more effective against armored enemies. It is also 10% faster to swing than the HF Blade and has boosted energy absorption.
It is also Jetstream Sam's primary weapon in the DLC.
A samurai sword dating back to the 16th century passed down the Rodrigues' family line for generations which was later upgraded with High-Frequency technology on Sam's request. Due to the already impressive quality of the original weapon, the Murasama boasts durability and cutting power far beyond that of standard HF blades.
It's stated in-universe that the name "Murasama" is an accidental mistranslation of Muramasa, a Japanese swordsmith whose infamous for making "cursed" blades.