Very often people ask me what the name tenkara means. When someone familiar with Japanese reads the name in Roman characters (tenkara), and not in the katakana characters (テンカラ), they read it as if it meant "from heaven". The sound ten normally means "heaven or sky", kara means "from". However, use of the katakana system of writing gives an indication that it may mean something else. How the name originated, nobody knows for sure. However, I do know how it became popular and what it currently means.
Tenkara was not always "tenkara" everywhere in Japan. Before it was widely known as "tenkara" throughout Japan, this method of mountain stream fishing was most commonly known as "kebari tsuri". You see, "tsuri" is the Japanese word for fishing. "Kebari" literally means "feathered/haired hook", and is the word for an artificial fly. Japan has a lot of mountains, and valleys. These valleys can be relatively isolated by the high mountains around them, and thus different dialects and words exist. One important note, the general, non-fishing population of Japan does not know the term "tenkara", and will look quizzically if you ask them about tenkara. In this case, using the term "kebari tsuri" may give them an idea that it is a method of fishing with a feathered hook.
In a few of these mountain stream areas, this method of fishing became known as tenkara very early on. There are several theories for how the name came about, though no one will ever know for certain. Fujioka-san presents a couple of theories for the name's origin in his site. One of the theories he does not cover, but is also widely accepted, is that one day a professional tenkara fisherman - the original tenkara angler - was casting his fly around a stream and catching a lot of fish. Someone not familiar with the method approached him and asked, "what kind of fishing is this?" (or something to those lines). The original tenkara angler misunderstood the question for, "how are you catching so many fish?", to which he replied, " well, the fish sees the fly coming from the sky - 'tenkara'... and when it lands, he bites." And so the word spread around that region that the method was to be called "tenkara". In other areas, people not familiar with the story just kept calling it "kebari tsuri", until...
Dr. Ishigaki, my sensei, started getting interested in tenkara about 40 years ago. At that time there was almost no information written or available. He found one book that talked of mountain stream fishing, "kebari tsuri" and gave a few pointers on the method. As he started devoting his time to researching tenkara, he was put in touch with many of the tenkara masters of the day. Some called it tenkara, others kebari tsuri. Suddenly, and in large part because of the research he was doing, articles he wrote for different magazines, and an appearance at one of the largest TV shows in the country, there was a resurgence in interest for tenkara in Japan. Many of the tenkara masters of the time started getting connected. Soon the word of choice for describing the traditional Japanese method of mountain stream fly-fishing, became tenkara. In part because it was shorter, part because it sounded more traditional and, in large part to be more specific and distinguish it from other types of fishing that used a "feathered hook".
So, what does tenkara mean? Tenkara means the "traditional Japanese method of mountain stream fly-fishing where only a rod, line and fly are used". Tenkara is a very narrowly defined word used exclusively to describe this exact method of fishing where only a rod, line and fly are used to catch trout in mountain streams.