Explanations (You'll probably need them, and they're many, so I put them beforehand):
hànzì - the letters used in Chinese. Most were based off of images, but they don't actually look as what they represent, due to their modification over time
kanji - the most complicated lexicon in the Japanese language, derived/borrowed from the hànzì characters from Chinese
hiragana - one of Japan's three alphabets; a phonetic syllabary with around 50 letters. Other properties of it can be found in the fanfiction.
katakana - another alphabet, with as many characters as hiragana.
Every hiragana letter has a katakana match. Both appeared from modifying the Chinese characters.
particles - parts of speech specific to the Japanese. The English somewhat equivalent could be considered prepositions and conjunctions.
hangul - the Korean alphabet, which is neither endless, nor used with another two, except for hanja
hanja - a few Chinese characters that slipped into the Korean language
Well, this is enough to get you started.
Yelling echoed off the Chinese-style walls. Looks like there was conflict again in the East-Asian household.
"NonoNonONO! You're doing it wrong!" Yào yelled in Kiku's room.
In the living room, Kiku raised his head from the manga he was reading, not surprised in the slightest. Slowly, he lifted himself from the sofa and, followed by Yong Soo's stare, walked upstairs.
When he arrived in his room, he saw Yào on the floor, looking through his diary.
"Yào-san, what are you doing?!"
He didn't get angry easily, but embarrassed? Hella. Nothing made him more embarrassed than his privacy invaded like that.
But, readers, do not get it wrong: He didn't intend to read Kiku's diary. He was searching for his own diary and he just couldn't find it! He decided to check Kiku's room, in hopes he'll find it there. And, oh, if he did… He would lose all trust in Kiku…
Unfortunately for him, Kiku's diary looked identical to his… A couple of months ago he bought them as matching souvenirs for him and Yào.
And, unfortunately for him, in his panic, the diary with white and crimson patterns looked like his. He frantically opened it, only to be struck by Kiku's sharp Japanese.
And he started reading… even though only the kanji were vaguely familiar to him. And the more he read, the more he wanted to let out a confused scream.
Kiku, seeing Yào didn't react, but look more and more confused and scared, screamed:
"Yào-SAN, PLEASE PUT MY DIARY DOWN, YOU INVADE MY PERSONAL SPACE!"
"WHAT THE HECK IS THIS?"
"Yào-SAN!"
"Do not worry, I do not care in the slightest about this Mediterranean dude you find hot, BUT WHAT IS THIS LANGUAGE?"
"Yào-san, that is Japanese ," Kiku spoke, as he snatched the red book out of the other's hands.
"B-but! The letters are so messy! My hànzì mixes with your hiragana and it all makes a huge mess! Nothing makes sense!"
Yào got up from the floor and ran to the wall library Kiku had in his room, grabbing the first book he laid his eyes upon, "The Tale of the Bamboo Cutter" , opening it swiftly, yet careful not to damage it in the slightest, since it didn't even belong to him.
"Look." He pointed to some round, feminine, curvy letters.
"I introduced you to kanji ..." he spoke, pointing at an intimidating block of text, "...and then you came up with this hiragana out of nowhere!" Yào exclaimed, tracing his finger back to the previous ones.
"Hiragana is used to write kana suffixes following a kanji root, for example to conjugate verbs and adjectives, parts of speech like particles, as well as native words for which there are no kanji or whose kanji form either obscure or too formal. Hiragana is also used to write furigana, a reading aid that shows the pronunciation of kanji characters."
Yào flipped a couple of pages. On the last pages of the book, he touched some sharp-looking letters, but simpler than kanji.
"And what is this? Their lovechild?"
Kiku did all he could to restrain himself from making a "pfttt " sound.
"That is katakana . We use it for words borrowed from languages other than Chinese, like English, Spanish and Dutch. It also has secondary purposes like writing emphasized words and onomatopoeia."
"Most countries complain about English influences in their languages; meanwhile you create a whole lexicon for them. I see how it is…"
"We had no choice. I mean we did, but it was better than what we used to do with ateji , you have to agree."
"Ateji ?"
"Words where my people borrowed hànzì to create words, based solely on their reading, resulting in messed up compounds. Like using Chinese characters to spell foreign words."
"Oh, I remember now! Like beikoku (USA). Literally, the rice country. When you think of the ricest country, it's mostly not the United States that comes to mind, is it?" Yào rhetorically asked, flexing his rice production on Kiku.
"Yeah. We used hànzì spelling out as a-mei-ri-ka , added the -koku (country) suffix. The pronunciation of the mei character (meaning rice) became bei . And overtime ameirikakoku shortened to beikoku . Etymology is truly out of this world." Kiku stared at the ground with an empty gaze, reflecting on his language's sins, like an anime protagonist.
"Yeah, I know… What a tangled language you have there. First, you borrow my letters. Then, you add two more syllabaries? One is a lot, but two? Why do you all, young countries, have to make new letters?"
"Yào-san, you created fifty thousand characters, which focus on meaning over reading. Not to mention you based them all on images," he talked back, raising an eyebrow.
"WeLL, nature is an amazing example to follow while constructing a language!" he yelled. "Not to mention you also borrowed them," he muttered.
"The hànzì for mother( 母 ) is a depiction of a woman's chest, Yào-san."
"Oh." He furiously blushed a deep shade of red. "Well… You're not wrong!"
"Not to mention the tones literally make the difference between mother and horse," Kiku continued."
"At least most hànzì have only one reading, not two different types of them, like your version of them."
"Well, one is derived from Old Japanese and the other from Chinese. You keep forgetting Japanese is not a language, but two big languages and more small ones on top of each other, wearing a trenchcoat."
"So it's a combination. Ah, yes, the Rìzhōng language."
"Since it's Japanese, we pronounce that as Nicchū ."
"Hm, nichu ?" Yào mispronounced the Japanese a little.
"Yeah, the nichu language. I can admit it's not the easiest."
"Ahahaha, unlike Mandarin. Chinese is so easy," he said proudly.
"Are you sure about that?" Japan asked, making a John Cena face.
"Well, we only have one alphabet, so that's nice!"
"How about bopomofo?"
"That's a Taiwanese addition. Not part of my Chinese."
"So you admit Taiwan is not in China?"
Yào pouted.
"I guess?"
"Anyway, as I intended to continue, due to less sounds and easier characters, I think that my language is easier than yours."
Yào looked at Kiku like he had been caught doing something bad, but was spiteful enough to try shaming the other with his offended look.
"Excuse you? At least Mandarin doesn't have verb tenses, or worse, degrees of politeness. WHO changes their whole language based on how much one respects another!?"
"Fair point. I think this debate might go on forever, so why not ask someone else which is easier?"
"Yeah, let's ask Alfred. He likes languages, despite the fact that his schools aren't really teaching any of them," he passive-aggressively responded.
"Good idea," Kiku said, taking out a phone out of one of his pockets and dialing the American's number.
"Wassup Kiku?"
" Moshimoshi Alfred-kun. Me and Yào-san are politely discussing the language barrier between us. We need an outside opinion on whose language is easier, so we are asking you, the polyglot."
"Aha, that's why? Honestly, out of all the east-asian languages out there, the easiest is definitely not Mandarin. It took me years to learn it and I still haven't finished… Too many characters…"
Yào squinted his narrow eyes, gazing downwards, looking like his soul just left his body.
"... but neither is Japanese. Don't get me wrong, it sounds cute; my bro, Matt is a weeb himself, but to me honestly, it's simply spoken too fast. And that's why it took me a long time to actually decipher Japanese."
Kiku's empty eyes turned even more dead as he asked Alfred:
"Then which language is the easiest?"
"Well, because of the relatively easy alphabet, hangul, which hasn't got thousands of characters, nor are they too hard to pronounce (except for hanja - the borrowed Chinese characters), the easiest language is pretty obviously Korean."
"WHAT?" the two yelled, shocked.
" I mean, it does have 7 degrees of politeness, but it's a nice language."
Suddenly, the door swung open, kicked by the strong foot of Im Yong Soo himself, who was spying on his oppas the whole time.
"Did somebody say Korean?"
The others shook their heads in disagreement, but were exposed by the American.
"Yeah, I did. It's the easiest east-asian language. K-pop for life. Now can I go back to doing my thing?"
"Haha, kanji 's origin might have not been in Korea, but you two wouldn't mind that now, correct?" he smugly affirmed.
Yào, being bitchslapped by two countries at the same time, forgot coherent English. Kiku, on the other side, kept his plain look, politely asking the Korean to quiet down, as he tried to hide the pieces of his shattered ego. Yong Soo cheered, like the two elders malding gave him manic energy.
The last things Alfred heard were frightened Japanese muttering, Chinese swearing and Korean yelling, until someone brutally hung up on him.
Other less necessary explanations and translations:
The notions of ateji, furigana can be understood throughout the context.
Rìzhōng/Nicchū - the reading for the word 日中, which derived from 日本(read as Rìběn(cn.)/Nihon(jp.), meaning Japan, and 中国(read as Zhōngguó(cn.)/Chūgoku(jp.), meaning China. You can probably guess the word means Japan and China, Sino-Japanese, etc. (it's their ship nameeeeeeeeeeee)
moshimoshi(jp.) - Hello! (on phone)
Please ask if you have questions, or tell me if my explanations are off!