The KARASAWA line of Laser Rifles is, along with the MOONLIGHT laser blade, a staple of the series. Named for one of the members of the Armored Core development series, the KARASAWA line of weapons is typically one of the most powerful weapons in the game along with the MOONLIGHT and former FINGER before it was nerfed.
Throughout Armored Core history, the KARASAWA has been a heavy and devastating energy weapon, typically the most powerful in game. It has undergone numerous changes but perennially consists of the same general shape and design. It commonly features 1500+ damage and usually around 50 shots. It is also extremely heavy and thus it's largely impossible to equip with much without utilizing a PLOW design.
The first member of the KARASAWA weapon line and in the mission Destroy Fuel Depot, the KARASAWA is a fast firing (near automatic speeds) Plasma Rifle that can finish off the most powerful enemies like enemy Ravens, the Devastator and Nine Ball in mere moments. It's fairly accurate but overusing it can lead to running out of ammo.
Appearing three times in Armored Core history, the KARASAWA remains a powerful and deadly weapon. Despite firing slower, it is very accurate and still very powerful. It also has a good deal of stun making it very dangerous. It is a powerful and respectable weapon.
Armored Core 3's only KARASAWA (save for Portable versions of Silent Line), this KARASAWA is notably the strongest and heaviest of the line. It is fairly fast firing and considerably more bulky in design but is still very deadly.
The weakest and lightest variant of the KARASAWA line, the KRSW had only 30 shots and dealt 1400 damage in Armored Core: Nexus but became more powerful in Ninebreaker and Last Raven with the rebalance of gameplay where it was given 40 shots and 1440 damage. It is also notable as being one of the "twin" weapons, which means that there are both left and right arm variants of this weapon.
Technically the same gun as the original MK2 model, this variant of the KARASAWA is much lighter than its counterpart, more damage but less ammo capacity. It is a very powerful and deadly weapon, especially as a wider range of weapons can equip it.
A Last Raven Portable exclusive, the KRSW2 is exactly as it's name implies: the KARASAWA-MK2 from Silent Line Portable and by extension Armored Core 2. It remains lighter and it's ammo gap is closed down a bit with it having 35 shots versus the 40 of the KRSW but has 200 some odd more drain and subsequently is a lot harder to use. Still it's absolutely devastating.
The CANOPUS appears as the KARASAWA in Armored Core 4. It is powerful but a bit slower in terms of firing and it's projectile is a bit slower than it was. Nevertheless it remains a powerful weapon.
Like in Armored Core: Silent Line and Last Raven Portable, Armored Core V features two KARASAWA weapons. The first is the Karasawa (in lowercase this time, unlike the past) and the second is the KRSW, continuing the naming continuity to its appearance in Nexus through Last Raven. The original is an extremely powerful weapon, having 10,000+ damage but only featuring 4 shots (more with Reserve Magazines) and it features an extremely long charge rate. However with this attack power (and Energy Amplifiers) it will devastate ACs, with just two shots, and most enemies will die in two attacks.
The KSRW is a much more economical version although not nearly as strong as one might think. It does have around 1000+ damage more than the nearest Laser Rifle but it also features far less ammo at only 40 shots. Still it does good in most cases, especially due to Laser Rifle's newly reduced recharge times.
At last, there is another version of the KARASAWA, called L-K37. It's a powerful weapon and represents an half-way between the other two models mentioned above.
The gun appears in Armored Core: Verdict Day as well.
- There is small class of laser rifles known as the "Mini-SAWAS" which were in essence, smaller, scaled down versions of the KARASAWA that also shared a somewhat similar appearance. An example would be the CR-WR98L from Last Raven or the CWG-XCMK/70 from Silent Line or the ZWG-XC/01 from Armored Core 2: Another Age.
- The Karasawa makes a player-usable appearance in 3D Dot Game Heroes - a From Software PS3 adventure game.
- The weapon's name is a reference to the producer of the original Armored Core Yasuyoshi Karasawa.