noun
iroha poem
A famous Japanese poem that uses each kana once, often used as an ordering system or for calligraphy practice.
いろは歌は「いろはにほへと」で始まる。
The iroha poem begins with 'iro wa nioedo'.
The name comes from the first three kana of the poem: い (i), ろ (ro), は (ha). The poem itself is traditionally attributed to Kūkai, but its exact origin is uncertain.