Iroha

The first appearance of the Iroha, in Konkōmyōsaishōōkyō Ongi (金光明最勝王経音義, 'Readings of Golden Light Sutra') was in seven lines: six with seven morae each, and one with five. It was also written in man'yōgana.

以呂波耳本部止
千利奴流乎和加
餘多連曽津祢那
良牟有為能於久
耶万計不己衣天
阿佐伎喩女美之
恵比毛勢須

Structurally, however, the poem follows the standard 7–5 pattern of Japanese poetry (with one hypermetric line), and in modern times it is generally written that way, in contexts where line breaks are used. The text of the poem in hiragana (with archaic ゐ and ゑ but without voiced consonant marks) is:

Note that archaic hiragana uses ゐ and ゑ, which are now only used in proper names and certain Okinawan orthographies. Modern writing uses voiced consonant marks (with dakuten). This is used as an indicator of sound changes in the spoken Japanese language in the Heian era.

An English translation by Professor Ryuichi Abe[2] reads as:

Although its scent still lingers on
  the form of a flower has scattered away
For whom will the glory
  of this world remain unchanged?
Arriving today at the yonder side
  of the deep mountains of evanescent existence
We shall never allow ourselves to drift away
  intoxicated, in the world of shallow dreams.

Komatsu Hideo has revealed that the last syllable of each line of the Man'yō-gana original (止加那久天之須), when put together, reveals a hidden sentence, toka [=toga] nakute shisu (咎無くて死す), which means "die without wrong-doing". It is thought that this might be eulogy in praise of Kūkai, further supporting the notion that the Iroha was written after Kūkai's death.[2]

The iroha contains every kana only once, with the exception of ん (-n), which was not distinguished from む mu in writing until the early 20th century (see Japanese script reform). For this reason, the poem was frequently used as an ordering of the kana until the Meiji era reforms in the 19th century. Around 1890, with the publication of the Wakun no Shiori (和訓栞) and Genkai (言海) dictionaries, the gojūon (五十音, literally "fifty sounds") ordering system, which is based on Sanskrit, became more common. It begins with a, i, u, e, o then ka, ki, ku... and so on for each kana used in Japanese. Although the earliest known copy of the gojūon predated the iroha, gojūon was considered too scholarly and had not been widely used.

Even after widespread use of gojūon in education and dictionaries, the iroha sequence was commonly used as a system of showing order, just like a, b, c... in English.

For example, Imperial Japanese Navy submarines during the Second World War had official designations beginning with I (displacement 1,000 tonnes or more), Ro (500 to 999 tonnes), and Ha (less than 500 tonnes). Also, Japanese tanks had official designations partly using iroha, such as Chi-ha (ha meaning the third model). Other examples include subsection ordering in documents, seat numbering in theaters, and showing go moves in diagrams (kifu).

Authorship is traditionally ascribed to the Heian era Japanese Buddhist priest and scholar Kūkai (空海) (774–835). However, this is unlikely as it is believed that in his time there were separate e sounds in the a and ya columns of the kana table. The え (e) above would have been pronounced ye, making the pangram incomplete.[4]

It is said that the iroha is a transformation of these verses in the Nirvana Sutra:

諸行無常
是生滅法
生滅滅已
寂滅為楽

which translates into

All acts are impermanent
That's the law of creation and destruction.
When all creation and destruction are extinguished
That ultimate stillness (nirvana) is true bliss.

The above in Japanese is read

Shogyō mujō
Zeshō meppō
Shōmetsu metsui
Jakumetsu iraku

• Ametsuchi No Uta (an earlier pangram)
• Japanese literature