Why the 50-Sound Kana Chart Has Only 46 Hiragana

The Japanese kana chart is called the gojūon, the “fifty sounds.” It has 10 rows, from the a row to the wa row, and 5 columns, from a to o. Ten times five is fifty cells. Yet modern hiragana has 46 basic kana.

The count works like this. Of the rows from a to ra, the eight rows other than ya have five kana each: 40. The ya row has three, や, ゆ and よ. The wa row has two, わ and を. That makes 45. Add ん, which belongs to no row, and you get 46.

So the ya row has two empty cells and the wa row three. Learners often ask why, and so do Japanese children. This article explains the gaps and the kana that once filled some of them.

The yi and ye cells

The ya row is the y sound plus a vowel: や ya, ゆ yu, よ yo. If the chart were perfectly regular, the i column would hold yi and the e column ye.

Yi is thought never to have been distinguished from i in Japanese, so there is no ordinary kana for it.

Ye is a different story. In very early Japanese, the e of the a row and the e of the ya row (closer to ye) are thought to have been separate sounds. The distinction is generally said to have disappeared by the Heian period, and no kana survived to write it separately.

That is why charts today either leave the yi and ye cells empty or repeat い and え there.

ゐ and ゑ in the wa row

The wa row is the w sound plus a vowel. It holds two kana that are no longer used: ゐ in the i column and ゑ in the e column.

ゐ is thought to have been close to wi and ゑ to we, distinct from い and え. Over time the sounds merged with い and え, but the spelling kept them apart for much longer.

The spelling distinction ended only in the twentieth century. The preface to Gendai Kanazukai, the current kana usage rules (Agency for Cultural Affairs, in Japanese), says that historical kana usage was the general standard from the Meiji era until the earlier “Gendai Kanazukai” of 1946 came into use. Until then, writing ゐ and ゑ was simply correct spelling.

The same rules include a comparison table with historical usage (in Japanese). Among words now spelled with い, it lists 井戸 (ido, well) and 居る (iru, to be) as once written with ゐ. Among words now spelled with え, it lists 声 (koe, voice) and 絵 (e, picture) as once written with ゑ: こゑ and ゑ.

There is no ordinary kana for wu.

Only を survived

The を in the o column of the wa row is also pronounced the same as お in modern speech. It survived because Part 2 of the rules says that the particle o is written を, as in 本を読む (hon o yomu, read a book).

In other words, を was kept as the kana for a particle. For more, see を or お, は or わ, へ or え: Writing Japanese Particles.

ん sits outside the chart

ん is not a consonant plus a vowel, so it fits no row or column. Charts usually place it outside the grid, next to or below the wa row. The 46th kana lives outside the fifty cells.

The iroha has 47

The iroha is a classical poem known for using each kana exactly once. It has 47 kana. It includes ゐ and ゑ, and it does not include ん.

Take ゐ and ゑ out of the iroha’s 47 and you have 45. Add ん and you have today’s 46. That accounts for the different numbers you may see.

Where ゐ and ゑ still appear

You will rarely see ゐ and ゑ in modern writing, but they have not vanished. Katakana ヰ and ヱ still appear in some company and product names.

The preface to the current rules says they do not apply where they are hard to follow, such as proper nouns. Names may keep their old spelling. If you spot one in Japan, you are looking at a piece of the old wa row.

A short answer for a child

If a child asks, I think this is enough: “There used to be letters here too. They came to sound the same as other letters, so people stopped using them.”

That way the empty cells are not mistakes but traces of the past. To me, the gaps are where the chart records how Japanese sounds changed over a long time. When you are learning the chart, you can simply treat them as cells you do not need to memorize. For how the chart is organized, see How to Memorize the Kana Chart: Learn the Rows and Columns.

The chart in StudyX Japanese Letters Table

StudyX Japanese Letters Table is a kana chart app where every cell plays its sound. The a row is on the right and the wa row on the left, the same order as a chart written vertically. In the developer interview I said: “Japanese is a language written vertically, so I followed that.”

In the ya column, や, ゆ and よ fill their cells and the i and e cells are empty. In the wa column at the far left, わ, を and ん appear from top to bottom, with empty cells between them. There is no ゐ or ゑ. You see today’s 46 hiragana, with the gaps left as they are.

Tap a kana and you hear it. There are no points or rewards; it is a tool for a child, or any learner, to check sounds on their own. The buttons at the bottom switch to katakana, romaji, and the dakuon, handakuon and yōon charts.

The app runs in landscape on both iPhone and iPad. On iPad there is a writing area under the chart for a finger or Apple Pencil. It is a one-time purchase with no ads and no in-app purchases. The on-screen labels are in Japanese. For a first session, see Getting Started with StudyX Japanese Letters Table.