剱 is the modern Japanese way to write sword.

This Kanji character comes from original Chinese. This form would also be understood in Chinese (there are often several ways to write the same character) but I suggest this one only if your audience is Japanese (because they've settled on a slightly different form as the standard in China).

In Japanese, this character also means saber/sabre, blade, bayonet, stinger, and clock hand (clock hands are the “swords” of the clock).

See Also:  Katana

气剑体一致 often gets translated as “Mind Sword Body,” or “Spirit, Sword, and Body as One.” But I think these translations don't tell you enough about what this is really saying.

In this context, 気, which is the modern Japanese version of 氣, means spiritual and unseen energy or “life energy.” In some cases, 気 can be translated as spirit, feeling, or nature. If defined as the mind, it's more about the invisible or intangible parts of one's mind (or soul).

剣 is the Japanese version of 劍 meaning sword.

体 is the modern Japanese version of 體 meaning body.

The Kanji 一 means one, and in this case, suggests “all in one.” The Kanji 到 means to send, deliver, or convey. But together, 一到 suggests all these things in agreement, union cooperation, or in concert.

Note: Arguments exist as to whether this should be romanized as Kikentaiitchi, Kikentaiicchi, or kikentaiichi. Technically, if you drop the last character, you get 気剣体一 and kikentaiichi (ki ken tai ichi), which is also a valid phrase.

真剣 is a Japanese word that means intense, serious, or earnest. It describes a person who is deep, serious, and a true thinker or dreamer.

Literally, this means “true sword,” as compared to a sharpened wooden practice sword blank. It's real, true, and serious.

合気剣 is Aiki-Ken, a style of Japanese sword technique.

武士の一言金鉄の如し is an old Japanese proverb about the value of the word of a warrior.

Here are a couple of versions of how this can be translated:

A warrior's single word is as unchanging and reliable as gold and steel.
A warrior's promise is as dependable as gold, and his [scabbard contains] untarnished steel (a sword).

Note: Sometimes this phrase is written as 男子の一言、金鉄の如し (danshi no ichigon kintetsu no gotoshi)

Note: Because this selection contains some special Japanese Hiragana characters, it should be written by a Japanese calligrapher.