Tekka (鉄火)

Tekka is the sate of red hot iron or sparks generated during forging. It also means smithery.

As for Netsu Tekka Shosho, see Juroku Shojigoku (the Screaming Hell).

Summary

Tekka originally meant the state of red hot iron as well as sparks generated by the forging process, and it came to refer particularly to teppo kaji (gun smithery) and also to katana kaji (sword smithery), latter of which has been closely related to Shinto rituals and samurai warriors. The word eventually came to represent swords and guns. It also came to mean swords and guns throwing off sparks in a battle. From that, the word tekka changed its meaning to battle field or war, then to dreadful scene implying war or death, or gambling. Meanwhile, tekka was used as a metaphor for kurogane (iron covered with black rust) changing its color to red, as well as for the state of red hot iron. It was also used as a metaphor that captured a characteristic of iron, 'easily heated but cools down just as easily,' because high thermal conductivity is one of the characteristics of metals.

Although there are words 'akagane' and 'sekitetsu,' which are similar to tekka, akagane means copper or an alloy with reddish gold color, and sekitetsu is ferric oxide (Fe2O3), or so-called red rust. Kurogane means iron and iron products covered with black rust because, since the ancient times in Japan, black rust has been produced on the surface of iron to maintain its strength by preventing red rust from corroding and weakening the iron. Chemically, however, kurogane means only ferrous oxide (FeO), or black rust.

Categorization of the meanings of Tekka

Those that are derived from the meaning, "sparks."

Tekka - guns and swords produced by smithery
Sword smithery and Gun smithery

Tekka - sparks flying through the air from swords and bullets from guns.

Tekka - describes bullets flying through the air and swords that are fiercely crossed, implying a battlefield or a dreadful scene.

Those that are derived from the meaning, 'red hot iron.'

Tekka - ancient trial in which one grabbed a red-hot iron bar to make a judgment on contentions. It is also called Higisho (the taking of a religious oath with red-hot iron).

Tekka - character of losing temper quickly. Character of picking up a fight quickly but letting go of the ill will just as easily. A woman who is brave and has mannish character.

Tekka - means 'maguro no zuke' which is red flesh of tuna soaked in soy sauce or soy-based sauce because the color of it looks like that of red hot iron.

Sparks
At first, tekka meant sparks generated from forging in smithery, then it came to mean sparks generated from swords in fierce fighting or sparks from a muzzle of matchlock gun. Tekka no ma' is a place or a space where sparks fly, implying a battle field or a dreadful scene.
From that, its meaning was extended to include gambling places which came to be called 'Tekkaba.'
Homeless gangsters who made a living by gambling, or common people who enjoyed gambling came to be called 'Tekka uchi' (gamblers). There is an anecdote that uses a word play, in which tekka-maki (literally means rolled tekka or tuna sushi roll) was a preferred food for good luck because it could be eaten as a simple meal between gambling matches.

Hyakuren Tekka - is a word that was used to describe various hard trainings and battles in which people engage with a fierce struggle, and it was used during the period of militarism, playing on words linked with hyakusen renma (experiencing various battles to become battle-wised).

In a passage of a noh play "Tamura," there is a line which describes 'Kijin (a fierce god) enveloped in dark clouds, throwing off sparks.'
In this scene, the word tekka can be considered to figuratively express thunder. A military song 'Lieutenant Colonel Tachibana (first)' (words by Tokusaburo KAGITANI, music by Toshitaka YASUDA), has the following phrase in the seventh verse of the song, which consists of 16 verses.
Sharpened swords and pikes throw off sparks in a furious battle.'
In addition, haiku poet Mio MIWA composed the following haiku, 'Emitting sparks in a smithy, plum blossoms in the night.'

Red hot iron
Trials

Tekka is a synonym of higisho (taking of a religious oath with red-hot iron), and trials held according to higisho is called 'tekka saiban' or 'tekka no saiban' (literally, 'red-hot iron trial,' in which one grabbed a red-hot iron bar to make a judgment based on the appearance of the burn on the hand).

Tekka zuka - a burial mound constructed to comfort spirits of the dead and to offer prayers at the site of higisho disputes over property line, right to enter a mountain, land ownership and so on.
In 1619, a Tekka trial was held in present-day Hino town, Shiga Prefecture, and to comemmorate this, 'the monument of Old Kisuke's Tekka trial' was built in the precincts of Unko-ji Temple,
Since ancient times, many places where higisho occurred have been considered sacred areas, and therefore, tekka zuka and tekka no doso-jin (traveler's guardian deities) exist in various places in Japan in order to comfort the spirits of the victims of conflicts. In some cases, however, burial mounds named tekka exist only because the area had smithies and the name of the town, villages or commonly used name of the area was Tekka or Kaji (smith).

Tekka Matsu (Tekka pine trees) - exist in Aoba Ward, Yokohama City, Tetsu Town (Yokohama City), and Yawara Village, Tsukuba City, Ibaraki Prefecture, as legend goes that they were planted to commemorate the settlement of conflicts over province or town borders by higisho, and since then, they have been called 'Tekka matsu' or 'Tekka no matsu.'
Tekka zuka also exist in Tetsu Town and Yawara village.

Character
As with 'maguro no zuke' (tuna soaked in soy sauce) in Edo-style sushi, the custom of using the term tekka to describe quick-tempered character can be considered to have developed especially in the shitamachi (traditional working-class neighborhood) culture of Edo in the Kanto region. Shitamachi in Edo is the birthplace of words shown below that are derived from the word tekka. There is a tendency of using tekka hada to express female character, whereas tekka denbo expresses male character.

Tekka hada
Tekka hada', or simply 'tekka' represents a character of a woman who fights at the drop of a hat, but who is frank and generous, and doesn't hold a grudge against anybody. Tekka hada is synonymous with 'Take wo watta yo' (straightforward), and was used as a word to express frank, manlike, and open-hearted female character.

Tekka denbo
Tekka denbo' is another word for 'denbo hada,' 'isami hada,' 'kioi hada' and 'ninkyo hada.'
It originally described characteristics of men who were rude and violent, and the word came from a legend in which a long ago, a gatekeeper of Denbo-in Temple in Asakusa, Taito Ward, Tokyo, did not pay his fees and behaved outrageously at nearby shops and show tents, taking advantage of the privileges of being associated with the temple. Later, however, the meaning of tekka denbo was combined with that of tekka hada to describe manly men who help the weak and crush the powerful.

Tekka geisha
Tekka geisha mainly referred to Tatsumi geisha in Fukagawa during the Edo Period. Shinagawa used to be a shukuba-machi (a post station town), and there were only non-licensed brothels (houses of prostitution) in Fukagawa.

However, in rivalry with Yoshiwara, Fukagawa flourished as a shrine town of Tomioka Hachiman-gu Shrine and also as a hanamachi (a red-light district) where Japanese-style restaurants and nonlicensed brothels were concentrated. In Fukagawa red-light district, geisha took center stage because there were no oiran (licensed prostitutes) and only a small number of joro (courtesans) existed, and therefore, 'Fukagawa geisha' and 'Yoshiwara geisha' were regarded as twin jewels of geisha, distinguishing themselves from 'machi geisha' in other regions. Under this circumstance, mannish temperament unique to Fukagawa geisha was born among the geisha who took pride in their work as a regular vocation, treating morally questionable drunken customers tactfully. It is said that some of the geisha even carried swords. They were called Tatsumi geisha because Fukagawa is located in the southeast (tatsumi) of Edo-jo castle.

Ninkyo mono (stories of chivalrous men)
Among movies depicted as contemporary and period dramas called ninkyo mono (stories of chivalrous men) in the Japanese film industry from the post-war period until about 1965, there were many movies whose titles were coined by combining words with tekka. They were Japanese movies dealing with violence or gamblers, or they were movies featuring women of tekka hada or tekka denbo men as the main character.
Representative examples include 'Tekka shamisen,' 'Tekka bugyo,' 'Zatoichi Tekka tabi,' 'Tekka botan,' and 'Tekka no Hanamichi.'

Maguro no zuke (tuna soaked in soy sauce)
In Edo-style sushi, red flesh of tuna was never eaten as they were. In most cases, it was eaten after being soaked in soy sauce or soy-based sauce In order to preserve the food as well as to kill harmful bacteria. Although tekka originally meant maguro no zuke (red flesh of tuna soaked in soy sauce), today, the word tekka has extended its meaning to red flesh of tuna itself, and it has been used not only for traditional dishes such as tekka maki (tuna sushi roll) and tekka don (a bowl of rice topped with tuna), but also to various dishes using red flesh of tuna.