Haiku, Tanka, and Senryu Character Rules | A Guide to Japanese Fixed-Form Poetry

Japan has a unique tradition of fixed-form poetry encompassing haiku, tanka, and senryu. Each form condenses expression within a strict framework of counted sound units (morae). This article explains the formats, character rules, the distinction between morae and characters, and how these art forms are enjoyed today.

Basic Forms of Japanese Fixed-Form Poetry

All three forms are structured by mora count. The table below summarizes their basic formats.

Haiku and senryu share the same 5-7-5 structure of 17 morae, but haiku requires a seasonal word (kigo) while senryu does not. Tanka adds a lower verse (7-7) to the 5-7-5 upper verse, creating space for deeper emotional expression across 31 morae.

The Difference Between "Morae" and "Characters"

In Japanese fixed-form poetry, what is counted is not "characters" but "morae" (sound beats). Understanding this distinction is the first step to proper composition.

• Each hiragana character generally corresponds to one mora (e.g., さ, く, ら = 3 morae)
• Contracted sounds (きゃ, しゅ, ちょ, etc.) count as one mora despite being written with two characters
• The double consonant marker (っ) counts as one mora
• Long vowel markers (ー) count as one mora
• The nasal sound (ん) counts as one mora

For example, "Tokyo" (とうきょう) is 4 characters but 4 morae: と・う・きょ・う. The contracted きょ counts as a single mora. Meanwhile, "chocolate" (チョコレート) is 6 characters but only 5 morae: チョ・コ・レ・ー・ト.

Ji-amari and Ji-tarazu Techniques

While strictly adhering to the prescribed mora count is the norm, intentional deviations exist as poetic techniques.

• Ji-amari (extra syllables): Adding 1–2 morae beyond the standard. Creates rhythmic variation and emphasis.
• Ji-tarazu (fewer syllables): Using 1–2 fewer morae than standard. Creates lingering resonance and pauses.
• Ji-amari in the first phrase (the opening 5 morae) is relatively natural and widely accepted.
• Deviations in the middle phrase (7 morae) significantly alter the rhythm and are considered advanced technique.

Matsuo Basho's famous "Furu ike ya / kawazu tobikomu / mizu no oto" (The old pond / a frog jumps in / the sound of water) follows a precise 5-7-5 pattern. However, poets like Taneda Santoka broke free from fixed forms entirely with free-verse haiku.

Modern Ways to Enjoy Fixed-Form Poetry

While fixed-form poetry may evoke images of classical literature, it remains widely enjoyed across all demographics today.

• Social media: The brevity of haiku and senryu pairs naturally with platforms like X (formerly Twitter)
• Salary-man Senryu: An annual contest featuring satirical senryu about modern work life that generates widespread media attention
• Haiku apps: Mobile services for composing and sharing haiku are growing in popularity
• Tanka renaissance: A resurgence of interest in tanka among younger generations, with poetry collections becoming bestsellers
• AI and poetry: Generative AI tools for haiku and tanka composition assistance have emerged

Surprising Trivia

Haiku is recognized as the world's shortest form of poetry and is practiced internationally. In English-speaking countries, "haiku" is composed using 5-7-5 syllables, and millions of haiku are estimated to be written worldwide each year. The International Haiku Association has members in over 50 countries, with haiku composed in English, French, German, and many other languages.

Why the 5-7-5 Rhythm?

The 5-7-5 mora structure is deeply connected to the natural breathing rhythm of the Japanese language. Seven morae is roughly the length a person can naturally vocalize in a single breath. Five morae provide a crisp, concise opening; seven morae offer sufficient space for development; and the final five morae leave a lingering resonance. This structure emerged naturally over centuries of poetic practice.

The addition of the lower verse (7-7) in tanka creates space for expressing emotions and introspection in response to the scene depicted in the upper verse. The 31-mora length has been refined over more than a thousand years as the ideal amount for exploring a single emotion in depth.

Common Mistakes

• Confusing "character count" with "mora count": The most frequent error. "Chocolate" (チョコレート) is 6 characters but 5 morae. Counting contracted sounds as 2 morae breaks the rhythm. Always count by morae.
• Forgetting the seasonal word, turning haiku into senryu: Haiku and senryu share the same 5-7-5 structure, but the presence of a seasonal word is the defining difference. A nature poem without a kigo is classified as senryu, not haiku.
• Unintentional ji-amari or ji-tarazu: These are advanced techniques, but when used unconsciously by beginners, they simply break the rhythm. Master the standard form first before attempting intentional deviations.

Pro Techniques

• Use "kireji" (cutting words) to create resonance: Words like "ya," "kana," and "keri" create a pause within the poem that stimulates the reader's imagination. The "ya" in Basho's "Furu ike ya" functions as a device that invites readers to imagine the stillness of the old pond.
• Understand the "hon'i" (essence) of seasonal words: Each kigo carries a "hon'i" — its inherent emotional quality. Cherry blossoms (sakura) evoke not just beauty but also the transience of falling petals. Using kigo with awareness of their hon'i allows you to pack deeper meaning into fewer morae.
• Read aloud when revising: The rhythm of fixed-form poetry is best verified by ear. Reading aloud lets you physically sense whether the breathing points and sound flow feel natural. Professional poets are said to always read their work aloud during revision.

Conclusion

Haiku follows a 5-7-5 pattern of 17 morae, tanka uses 5-7-5-7-7 for 31 morae, and senryu shares haiku's 17-mora structure. These patterns were refined over more than a millennium based on the natural breathing rhythm of Japanese. The most important point is counting by "morae" rather than "characters," and accurately understanding the treatment of contracted sounds and long vowels. Use Character Counter to check your character and mora counts.