Is there a difference in drawing between the "mouth" and "enclosure" kanji radicals?


The two kanji radicals from the image are supposed to be 2 different kanji
radicals, one meaning "mouth", and the other meaning "enclosure". I'm not sure
if they are supposed to look different or not. The one above seems to have
some very small lines continuing the box, but may be it's just my imagination.

I noticed one of them is used in kanjis where a drawing goes inside it, and
the other doesn't have any drawing inside it. Is that supposed to be the
difference between them or they look barely different somehow?

[![enter image description
here](https://i.stack.imgur.com/Vlarx.jpg)](https://i.stack.imgur.com/Vlarx.jpg)




In printed form, they are the same except for their size. Mouth is smaller
than enclosure. Enclosure _encloses_ other radicals or kanji, but mouth never
takes anything inside it.

Some common kanji enclosed by enclosure:

> 国 四 回 団 図 園 因

Notice how 「回」 has both 囗 (enclosure) and 口 (mouth).

In 楷書 (regular script), they look almost the same. They are drawn with the
same strokes, but the second stroke of 囗 (enclosure) can be a bit longer than
in 口 (mouth) and the final stroke of 囗 (enclosure) is drawn after the enclosed
part. In regular Japanese handwriting, the stroke length difference might be
less noticeable or not there at all. See this stroke order animation of 「回」 in
regular script:

[![回](https://i.stack.imgur.com/MkCMZ.gif)](https://i.stack.imgur.com/MkCMZ.gif)

In 行書 (running script, semi-cursive script), a fairly common and well-
understood calligraphy style, they look different. See this image of 「回」 in
running script:

[![回](https://i.stack.imgur.com/945l5.gif)](https://i.stack.imgur.com/945l5.gif)

In addition, there are other calligraphy styles that use historical radicals
or simplify the radicals as seen fit for a particular character. See
Earthliŋ's answer for more details about historical forms of 囗 and 口.




The two radicals 口 and 囗 are indeed different, even though they are hard to
distinguish in modern scripts/fonts. This "standardization" of unifying the
looks of unrelated elements is somewhat intentional (presumably to make the
script more homogeneous). You can see the same thing happening with 月 and 肉
(see [Is there any reason a lot of body parts use the Month/Moon
radical?](https://japanese.stackexchange.com/q/44763/1628)) and the radical ⺍
unifying various elements such as the top parts of 學、螢、巢、…

Back to the difference between 口 and 囗.

As you noticed, 口【くち】 is a Chinese character.

囗​ 【くにがまえ】 is not a (traditional) Chinese character, but only appears as an
element (signifying "enclosure") in characters such as 国・國、圓、図、…

The difference is visible in historical scripts (screenshots from Wiktionary
for [口](https://en.wiktionary.org/wiki/%E5%8F%A3) and
[囗](https://en.wiktionary.org/wiki/%E5%9B%97))

[![口](https://i.stack.imgur.com/TELUH.png)](https://i.stack.imgur.com/TELUH.png)
[![囗](https://i.stack.imgur.com/zApon.png)](https://i.stack.imgur.com/zApon.png)

as well as in handwriting.

The next pictures show them "in action" as part of a different character:

[![enter image description
here](https://i.stack.imgur.com/1T99k.png)](https://i.stack.imgur.com/1T99k.png)

The top row is a standard _Minchō_ font, the middle row a _Kyōkashotai_ font,
and the bottom row are their historical renderings taken from
<http://www.chineseetymology.org/>.

As 囗 くにがまえ has something inside them, the vertical strokes are parallel also
in handwriting, whereas the vertical strokes in 口 くち are slightly angled.

* * *

_Note._ 口 and 囗 should not be confused with _katakana_ ロ _ro_.

