In Japan, the consumer is known to be very demanding. They are willing to pay top dollar for golf equipment but they only expect the best when it comes to materials, design and workmanship. The Japanese golfer is also very educated technically speaking when it comes to golf gear. Like their passion for electronics and gadgets, the Japanese golfer is also a the ultimate equipment junkie. It is because of this that so many golf publications with such detailed technical tests on clubs can exist in Japan.
I'm going to take a look at the basics of golf gear using the lingo and view of the Japanese golfer. They believe knowing clubs inside out technically, along with detailed tests and real life testing of clubs will ultimately result in the best set for each golfer. Unlike in the western world where we use terms like scratch golfer, low handicapper, high handcapper etc., the Japanese group golfers pretty much into three groups. Pro Golfer, Athlete Golfer, Average Golfer. It actually is a bit more vague classifying golfers this way but it does the job.
When looking at an iron at address, there are basics that can tell you alot about that iron and who its target audience is. Irons are classified into three groups, compact head, mid sized head and big head. All three of these head types have the following 6 basic characteristics to look at:

Most of this is pretty common stuff but it is possible that most recreational golfers outside of Japan don't necessarily look at all these characteristics and what they mean to the golfer. As you can see from above, there are some different terms use. The Japanese like referring to the Top Line as Top Blade (though some of us probably use this as well). They rarely use the term offset (most manufacturers measure face progression anyway), instead opting for a neck type classified as goose neck, or semi goose neck or if no goose, them straight neck. Of course this is in reference to lots of offset, medium offset, minimal to no offset. Now there are some intersting things here like heel height, toe shape, top blade roundness. How does that affect performance or target audience? We'll find that out in part two cause I hate writing too much at one time. (^_^)