Sword Art Online Wiki
Sword Art Online Wiki
Warning.png Spoiler Alert: This article or section contains details about plotlines not covered in the anime. Do not proceed unless you wish to be spoiled.

«Kagemitsu G4» (カゲミツG4, Kagemitsu G4?) is a photon sword (フォトンソード, Foton Sōdo?) sold for 150,000 credits in Gun Gale Online. The sword is alternatively referred to as a «Kouken» (光剣(こうけん), Kōken?, lit. "light sword"), laser blade, lightsaber or beam sabre.

A black Kagemitsu G4 with a purplish-blue energy blade[1] was purchased by Kirito and used as his primary weapon in Gun Gale Online.


A Kagemitsu G4 is a metal, tube-like weapon[1] that is 3.5 centimeters in diameter and 19.8 centimeters long.[2] On one end, a metal tool that looks like a mountaineering carabiner hangs down.[1] The aperture end is slightly thicker with a black hole in the center.[1] The colour of the weapon can be customised, with twelve choices available[2], and the energy blade emitted is one meter long.[1]

Compared to ordinary swords, the 800 gram[2] Kagemitsu G4 is lighter in weight, which is its main advantage in GGO.[1] However, it also has continuous usage limits due to overheating, as well as battery limits.[3]


Phantom Bullet Arc[]

Kirito bought a «Kagemitsu G4» because it was the only weapon he had found that resembled a sword, which he preferred as he was used to clashing with swords in Sword Art Online and ALfheim Online. Kirito was quite proficient with this saber, as he was able to slice up bullets flying at him. Despite being a photon sword, it is unable to cut through all materials, as shown when pitted against the Starship Metal Estoc.



  • The Kagemitsu G4 was introduced to the game by the whims of the creators to resemble the Lightsabers from the popular science-fiction movie series Star Wars.
  • After Kirito's appearance in the third Bullet of Bullets, the photon sword experienced a great rush of popularity, but no one was able to deflect bullets with any skill resembling Kirito's. Sinon was among those who tried it without success.
  • A bugged sword named Kage■tsu_4[† 1], similar to the Kagemitsu G4 but with a red blade, is available in Sword Art Online: Lost Song as a possible drop from the Black Lotus extra quest. An identical sword is also available as Downloadable Content (DLC) in both Sword Art Online: Hollow Fragment and Sword Art Online Re: Hollow Fragment, under the names Photon Sword and Lightblade: Photon Sword, respectively.


  1. The name of the sword is changed to Ka+@e_su%204 in the English localization.



SAO Weapons Anneal Blade - Dark Repulser - Ebon Dagger - Elucidator - Guilty Thorn - Karakurenai - Lambent Light - Liberator - Mate Chopper - Stout Brand - Sword Breaker - Throwing Pick - Tyrant Dragon - Wind Fleuret
Argyro's Sheet - Blackwyrm Coat - Coat of Midnight - Cor - Crystal Bottle of Kales'Oh - Crystallite Ingot - Crystals - Divine Stone of Returning Soul - Dusk Lizard Hide - Eternal Storage Trinket - Hand Mirror - Mighty Strap of Leather - Mirage Sphere - Pneuma Flower - Potions - Ragout Rabbit's Meat - Ring of Agility - Ring of Angel's Whisper - Scavenge Toad Meat - Tremble Shortcake - Vendor's Carpet - Yui's Heart
ALO Black Iron Great Sword - Blue Long Sword - Crest of Yggdrasil - Demonic Sword Gram - Holy Sword Excalibur - Lightning Hammer Mjölnir - Long Sword - Sap of the World Tree - Yrd
GGO Accuracy International L115A3 - Credit - Defense Field - FN Five-Seven - GE M134 Minigun - Kagemitsu G4 - Metamaterial Optical Camouflage Mantle - PGM Ultima Ratio Hecate II - Plasma Grenade - Procyon SL - Satellite Scan Terminal - Starship Metal Estoc - Type 54 "Black Star"
Project Alicization Black Lily Sword - Blue Rose Sword - Conflagrant Flame Bow - Divine Object - Dragon Bone Axe - Fragrant Olive Sword - Frost Scale Whip - Gigas Cedar - Goblin Sword - Heaven Piercing Sword - Night Sky Sword - Silvery Eternity - Time Piercing Sword - Twin Edged Wings