Is your iPhone using the correct default font for Japanese text?

Today I want to tell you about a little quirk of the system which I encountered when playing with iOS7.

With successive releases of iOS, Apple occasionally add new fonts to the system. Aside from app developers, it is something to which most of us are probably oblivious. There aren’t that many apps where a user has the need or opportunity to select a font (iBooks being an exception). Probably the majority of developers opt to stick with the default system font, which offers a clean and simple look and ensures their UI looks and feels like it belongs on the platform.

I don’t know if this was the case in earlier iOS versions, but there are currently different default system fonts used for each out of Chinese, Japanese and Korean.
When an iPhone displays Chinese, Japanese or Korean text, it will begin by looking in the current system default font for the required character. If it doesn’t find it, then it seems to fall back to the default system font specific to the language with which that character is primarily associated.

The default system font is changed when switching between the three languages, and because all three fonts contain the Japanese Hiragana and Katakana characters, Japanese text will appear different when the iPhone system language is set to Chinese or Korean.

All pretty straightforward so far, but… if you happen to be using your phone to display Japanese text, while the system default language is set to anything other than Chinese, Japanese or Korean, which font does it choose?

If you’ve never switched the system language on your phone, then the answer is probably that it picks the “correct” default font.

However, if you (or someone else before you) has had the phone operating in Chinese or Korean and then changed it to English (or another language), then the default font for all CJK characters will be the one associated with the most recently used system language out of the three.
In other words, if I type some Japanese text into Notes or Mail and then switch the iPhone to operate in Korean, when I open my note or draft mail the font used for the Japanese text will have changed. But if I then switch the phone back to English, it will continue using a Korean font as its first choice when displaying Japanese text. To fix this, I would need to switch the phone language to Japanese, and then back to English again.

Here is a side-by-side comparison of the three fonts being used to display Japanese Kana. From left to right the fonts are the defaults for Chinese, Japanese, and Korean.

If you’d like to try this for yourself, please make sure you note down the navigation path through Settings to the language options before switching your phone into a language which you can’t read. 😉
On the language menu:
Chinese (simplified) is 简体中文
Chinese (traditional) is 繁體中文
Japanese is 日本語
Korean is 한국어
At the time of writing, in Settings, General is the first item in the third group. Then International is the third item from the fifth group. After that, Language is the first item, and from there you can revert.