The Kanji: 口 (Kuchi/Kō) - The "Mouth" Kanji
The kanji "口" is one of the simplest and most fundamental characters. It is a direct pictogram representing a "mouth." Its meaning extends to any mouth-like opening, such as an entrance, exit, or a spoken word.
1. Meaning and Usage
Core Meanings: Mouth; opening; entrance; gateway; spoken word.
Readings:
Kun'yomi (Japanese reading): くち (kuchi)
On'yomi (Chinese reading): コウ (kō), ク (ku)
Common Words and Compounds:
口 (くち / kuchi) - Mouth
入口 (いりぐち / iriguchi) - Entrance
出口 (でぐち / deguchi) - Exit
口座 (こうざ / kōza) - Bank account (Literally "mouth seat")
人口 (じんこう / jinkō) - Population (Literally "person mouths")
2. Writing and Stroke Order: A Simple Square
The correct kanji writing for "口" is deceptively simple. While it looks like a square, it has a specific stroke order and subtle proportions that distinguish it from the actual kanji for "square" (四).
Stroke Order:
Stroke 1: Left vertical stroke. Write from top to bottom.
Stroke 2: Top horizontal and right vertical stroke in one continuous motion. Start at the top-left corner, go right to form the top, then turn downward to form the right side.
Stroke 3: Bottom horizontal stroke. This final stroke closes the box from left to right.
Significance of Correct Kanji Writing:
Proportions are Key: The character should be slightly smaller and more square-like than tall. The bottom horizontal stroke (Stroke 3) should be slightly wider than the top, giving it a stable, "sitting" appearance.
One-Stroke Corner: The second stroke, which forms the top and right side in one fluid motion, is a fundamental technique in kanji calligraphy and writing. It creates a cleaner, more professional look.
Radical Recognition: As the "mouth" radical (くちへん), it appears in countless other kanji related to speech, sound, and openings (e.g., 言 - to say, 語 - language, 叫 - to shout, 聞 - to hear/to ask).
3. Historical Origin and Evolution
The history of "口" is one of the clearest examples of a pictogram in the Chinese script, remaining almost unchanged for millennia.
Oracle Bone Script (甲骨文字):
The earliest form was a simple, clear pictogram of an open mouth. It was often drawn as a U-shape or a slightly rounded square, vividly representing the lips and the cavity of a mouth.
Bronze Script (金文) & Seal Script (篆書):
The form became more standardized and squared off, as the tools for writing (bronze casting, brush, and ink) favored straight lines over curves. However, the representation of a mouth remained completely unmistakable.
Modern Form (楷書):
The modern "口" is the final, fully squared-off version of the ancient pictogram. While it has lost its curved, organic shape, it has become a highly efficient and universal symbol. The character's form is a perfect abstraction—it no longer looks like a detailed drawing of a mouth, but we intuitively understand it as one.
Cultural and Conceptual Connection:
In Japanese culture and language, "口" extends far beyond the physical organ.
Speech and Communication: It represents the faculty of speech. Having a "heavy mouth" (口が重い) means to be taciturn, while a "light mouth" (口が軽い) means to be a blabbermouth.
Openings and Gateways: It symbolizes any kind of opening, from the entrance to a building (入口) to a mountain pass.
Units and Counters: It is also used as a counter for mouthfuls or for household members.
Summary
The kanji "口" is a perfect starting point for understanding the logic of kanji. It began as a literal drawing of a mouth and evolved into a clean, abstract, and versatile symbol. Mastering its stroke order and subtle proportions is a foundational step in Japanese kanji writing, as it introduces the crucial "enclosure" structure and appears as a radical in hundreds of other characters. When you learn how to write kanji like "口," you are not just learning a word for "mouth"; you are learning a fundamental building block of the written language, a character that gives form to words, passages, and the very act of communication itself.