Airsoft, as we know it today, originated in Japan in the 1980s, when people, unable to possess real guns, wanted high quality replicas (which also fired something).

Manufacturers of gas guns such as MGC, JAC and ASAHI dominated this period of Airsoft and some of the most sought after airsoft pieces (often with a high metal content) came from these manufacturers in this era. However, as skirmishing with airsoft guns took off, fuelled by the availability of CO2 and compressed air powered automatic guns, with external gas tanks (which, although bulky, worked well on cold days), The demise of classics occurred because the Japanese government banned Green Gas and CO2 over there, so they were left essentially with 134a, an underpowered and expensive propellant.

JAC lasted through 1995 and Kokusai through 1997 producing gas rifles, though they continued making their pistols and revolvers after that. Asahi discontinued their gas guns and went to limited production guns, as far as is known exclusively bolt action. Maruzen, the maker of the Mac10 and 'mini' AUG (86% scale aug), popular beginner's guns, has continued with their smgs and pistols to this day.

It was around this time that Tokyo Marui launched their AEG (Automatic Electric Gun) range, which require no gas and work whatever the weather. The effect of these, long arms (rifles and machineguns) was to drive most of the traditional (gas gun) manufacturers out of business.

Of course, there were collectors of handguns who still wanted gas guns (the handgun equivalent of AEGs, EBB, is a damp squib so far) and manufacturers such as Tokyo Marui, Western Arms and KSC stepped in to produce, first NBBs and then GBB pistols, whilst old timers like Marushin and Maruzen stayed in the market producing their range. These guns had more efficient gas systems, which meant that a reasonable amount of gas could be stored in the magazine (or hand grip on earlier NBBs), removing the reliance on ugly external tanks and increasing the realism.

Airsoft guns were designed to be relatively low in power so that they could be used in confined spaces as space is at a premium in Japan. The combination of realism, safety, flexibility, and low cost made Airsoft more appealing to the average consumer who would like to exercise his or her steady eye! hand coordination without the inherent dangers. Some real steel owners like to practice with their GBB as the cost of ammunition is something like 1/100th of the price!

Springers have been around a long time (I owned a Daisy spring .177 once!) and they form the cheap end of the market, with prices ranging from £5 or £6 for very cheap, weak and poorly detailed Chinese made guns (often bearing little or no resemblance to any specific model) to around £60 for top of the range KWC Desert Eagles, with adjustable hop-up and GBB like quality and they continue to

Today, Airsoft is popular in many of the Asian countries and gaining in popularity, for both collecting and skirmishing (where the lower pain infliction and increased realism is winning converts from paintball) in the US and Europe (notably Italy and the UK).

Interestingly, whilst the AEG is the preferred long arm for most skirmishers, there's a thriving market for gas blowback rifles and sub-machine guns and these are becoming better and more powerful as the technology developed for airsoft handguns is applied back to them.

Paul Whitney wrote to correct a "few mistakes"

Tanio koba built the first blowback airsoft gun for MGC in 1985, it was a glock I believe.

Co2 in bulk quantities was and IS illegal in Japan for non-industrial use. Gas guns may also NOT run on unregulated liquid co2. Compressed air and nitrogen were the only options outside of flon which was known as r12. R12 became very expensive when the ban occurred due to environmental impact thus they switched to 134, a considerably high power gas than r12. C02 IS green gas in japan. If you ask for green gas they will hand you a small co2 bulb with a screw on top. R22 is not allowed in Japan due to JASG regulation and not the government.

JASG is a corporation which dictates factory standard powers which cannot be exceeded without modification and/or warranty voidance.

Kokusai still produces hand guns of varying degrees on a regular basis.

Asahi is no longer in business, but is a new incarnation formed by ex-employees of Asahi and Killer Studios.

WA and KSC are some of the longest running companies. WA holds many specific patents which limits other companies ability to produce mechanisms without paying a fine.

KSC bought the entire MGC plant as they were on the way out. KSC is the only company that builds and designs all guns in house...all others are subcontracted.

Power limits were defined by the government based on parameters set forth for hunting airguns and further focused by the corporations controlling ASGK and JASG."

Oik (from UKAN Forum), posted this 'potted history'.

I read several articles a while back that had the history of airsoft / soft-air going back 30-40 years.

It seems that modern airsoft has its roots in both america and japan.

In America the famous 'daisy' air gun range was expanded in the 1970s with handguns that fired lightweight round pellets, stored in shells, very similar to todays airsoft revolvers. these were called 'soft-air' pistols. These used a simple spring-powered air piston to fire the pellets and were short ranged and low powered. by the end of the 1970s, early 1980s these were introduced to the japanese market.

In Japan, ownership of real firearms had been banned since the 1960s, and since japan is well known for their model-making hobbies, the gap made by banning real firearms was quickly filled with dummy replicas and model-cap firing [not like western paper-strip cap guns, but more akin to blank firers, with full-auto capability] - these were highly detailed models of the real things and were highly collectable items (These dummy and model-cap guns are still made today by hudson, marushin, etc)

With the advent of the daisy low-power system, the japanese modelers took to adapting this system to power their model replicas.
With the low power of the guns, coupled with the highly detailed models, made the ideal, completely legal, non-lethal, real steel replica firearm. and these soon become common in the japanese markets in the 1980s known as soft-air or air-soft.
By the mid 1980s, not only were there the common spring-powered gun available in every possible model, there were gas [freon gas, co2, etc] powered guns too, and with these metal replicas, the power levels were raised beyond the simple air-powered plastic models.

I recall in the 1980s that two things were becoming very popular in the uk - paintball gaming and japanese imported plastic model car kits: tanks, planes, ships - either r/c or plastic models - all very highly detailed and very popular. it seems to me that the early airsoft guns were imported like any other plastic model kit, since that's all that they were, and the power levels and range were so low and short, and being made of cheap plastic, they barely made an impression above kids toys of similar energy-output.

Springer kits [make your own gun] were widely available in the model hobby shops by the end of the 80s, early 90s, with both pistols, rifles and shotguns being available.
Gas-power gave way to cheaper-to-make plastic AEG's in japan in the early-mid 1990s, and these slowly made their way to the uk.
the rest is recent history...

[hop-up seems to have been added in the early 1990s, since none of my early springers have this, tho the first TM aeg, famas has it]

As for skirmish sites, i recall speaking to someone who said that they probably set up the first purposely-run skirmish site for airsoft in the uk in the early-mid 1990s, using the first AEG's that had come out of japan.
No doubt airsoft may have been skirmished before but it may have been privately or also on previously existing paintball sites.
It seems that the late 1990s saw the rapid expansion of sites, using airsoft-only and paintball game sites.

As for the introduction of airsoft to the uk, it definitely wasn't because of the real steel bans because the introduction of airsoft preceded the most stringent of gun bans by some 10-15 years.
What the gun bans did tho was probably increase the ownership of airsoft, although always playing second fiddle to the more common and more powerful airguns, which didn't have the stigma of 'childs toy' stuck to them like airsoft did [and still has].