Safety: Always wear goggles when you handle an airsoft gun, even if you're shooting at targets. The most important safety is not any feature of the airsoft gun, but how it is handled by the user. These are the most important things to remember: Never point the muzzle at anything you are not willing to shoot.
The first rule simply means that the two other rules are followed without question.
Most of the text in the KSC manual is background information and similar details, which do not affect the operation of the model. There are general key points to operating a GBB (Gas BlowBack) model, and they apply to virtually all models regardless of brand and exact model.
The KSC manual has clear illustrations about the use, maintenance and safety features, so I would kindly advise to refer to those, even though the text is in Japanese. I'll provide key points to the use of these models here. The text follows the manual, so please keep it opened for reference.
1) Press the magazine release button to release the magazine.
2) Pull the magazine spring retainer towards the top of the magazine, and slide the floorplate towards the front to reveal the gas fill valve.
3) Holding the gas bottle (Green Gas / Propane or HFC 134a) upside down, press the nozzle to the fill valve to fill the magazine.
3b) It will hiss out some gas during filling to allow the liquid propellant to enter the magazine. Fill until the liquid spurts out: The magazine is then full. (Because of the liquid charge, do not shoot the pistol sideways or upside down.)
Avoid temperatures higher than 40C/100F, and naked light or direct sunlight. Green / Top gas is propane (C3H8), so the necessary cautions for propane apply to gas airsoft guns as well.
pg7: It is not advisable to press the main valve behind the magazine, when the magazine is full of gas. It will vent the gas and could potentially damage the seals.
pg8: The follower may be locked down to make loading the BBs easier. Do not let the follower snap up freely. 23 BBs may be loaded in two columns. Before inserting the magazine, please check that the BBs can compress down by 3 mm. You may then insert the magazine.
pg9: After inserting the magazine, pull the slide back, and release it. Do not ease it forward, but release as if you were shooting a bow and arrow.
The middle trigger safety (if present) may be flipped up for additional safety. The pistol does not have other safety features.
pg10: When you shoot, an internal hammer knocks the valve open to operate the pistol. Gas propellant is used to cycle the slide. Please keep thumbs on one side of the pistol to avoid getting hit by the slide. Also, do not hold the pistol close to your face to aim.
pg11: After the last round, the slide will lock back. Double-check the chamber to make sure the pistol is empty.
pg13: Hop-up (backspin) adjustment. Please use the supplied tool to adjust hop-up to get a desired straight trajectory. Turning counter-clockwise adds the spin, clockwise reduces.
pg15: Unload the pistol when you stop using it, put it in a case and away from children or other unauthorized persons. When transporting, do not brandish it in public as it would alert other people and the authorities. The police will treat it as if the pistol was real, despite the orange tip.
pg16: Indicates where to add silicone oil to maintain the rubber seals. Only add silicone when the magazine is empty, so it doesn't vent gas when you press the main valve. After adding silicone, press the valve a few times to get the silicone into the valve.
pg17: The flipper part below the slide should be kept clean and lubricated. Generally all moving parts should be cleaned and lubricated periodically (every 1000 shots, or more often). Please use only 100% silicone oil to avoid damage to the rubber and plastic parts. Mineral oils may attack the plastics.
pg18: Disassembly: Remove the magazine, rack the slide to cock the hammer, pull the slide lock down on both sides and the slide comes off forward. (The G18C selector has to be in the middle position for disassembly.)
pg19: Diagram of the inner barrel and hop-up system. Normally do not disassemble.