89. The "Mixing" Radical: 爻
This radical appears in exactly one Joyo kanji:
爽 (2053: refreshing)
And some sources don't even agree with that categorization; Breen considers this kanji to have the on-duty 丿(4: "katakana no") radical, whereas Halpern, Nelson, and Kanjigen file it under 爻.
My proofreader also votes for 爻, as that reflects its location in the Kangxi Dictionary, which is the basis for how most Japanese dictionaries have in turn categorized kanji radicals.
That settles it—we'll treat 爽 as our shining example of radical 89!
Incidentally, Kanjigen tells us that in 爽, the four X shapes symbolize either "a woman's breasts" or tattoos. The 大 represents "person." So the character may indicate that that person had two breasts on the left side and two more on the right, which makes me wonder just how many breasts ancient Chinese women had! And did people tattoo themselves way back then?
What Do the Japanese Call the 爻 Radical?
When it comes to the Japanese names of the 爻 radical, there is again a startling lack of consensus.
Nelson has まじわる.
Halpern has めめ.
Kanjigen has こう, めめ, and ばつばつ.
That assortment seems awfully random until you consider that the 爻 shape is also an autonomous, non-Joyo kanji:
爻 (コウ, ギョウ, まじ•わる: to mix with, associate with; join)
Ah, that explains the names こう and まじわる, and the "mixing" connection. Speaking of "mixing," Nelson calls 爻 the "to mix" radical (what awkward syntax!), with the nickname "Double X." Now, that I like. It sounds very James Bondish.
The めめ refers to the katakana メ, as 爻 resembles a stack of two メs. Similarly, ばつばつ is about the duplication of X shapes. The Japanese refer to the X symbol as ばつ, as in tic-tac-toe.
We'll go with こう.
An X-Rated Radical
Radical 89 may not have always had two Xs. Compare these images of the ancient 爻 shape from Richard Sears's page:
In the bronze section, most of the shapes had triple Xs! As for the last array, those look like early attempts at hashtags!
(For explanations of the three category names on Sears's page, go to the Joy o' Kanji Glossary and read the last section.)
Just for fun, here are Sears's old images of the non-Joyo 爾 (thou, you; so in that way), one of the very few characters Nelson includes in his radical 89 section:
What craziness!