[Tell Me, Chappy!] The Correct Way to Read "Japan"

This is sudden, but I absolutely love Korean dramas, especially historical ones.
I don't know how many times I've watched "King's Daughter, Soo Baek-hyang".
Recently, I've been watching the clips of that same show that pop up in my YouTube recommendations,
and even though I don't understand Korean at all, I follow the story perfectly.

But that's not what this is about.
The other day, there was a scene in that story where Japan appeared as the neighboring country "Wa," and a simple question popped into my head.
When did Wa start being called Japan? Furthermore, there are two ways to read "Japan" (Nihon/Nippon), so is one of them correct?

The public broadcaster, Nippon Hoso Kyokai (NHK), uses "Nippon," the Bank of Japan is "Nippon Ginko," and stamps are marked "NIPPON," so I personally thought "Nippon" was the official one. However, when I looked into it again, it seems "Nihon-koku Kenpo" is the common way to say the Constitution of Japan, and when I listen to press conferences by members of the Imperial Family, they seem to say "Nihon."

So, this time, I asked my Chappy about the correct way to read "Japan," and I hope you'll bear with me.

Conclusion: Both are "correct readings"

The country name of Japan is considered officially correct whether read as "Nippon" or "Nihon".

• The government (Cabinet Secretariat) and the National Language Council have clearly stated that they "have not unified it to one or the other."

• While NIPPON is often used for English notation on passports, banknotes, and stamps, Nihon is common in domestic conversation.

In other words, both are accepted, both officially and in daily life.

The differences and background between "Nihon" and "Nippon"

1. History of etymology and sound changes

Both readings originally come from the Sino-Japanese reading of the kanji for "Japan" (Nippon/Nihon).

• It is believed that "Nippon" was the reading used originally.

• However, because a sequence of sounds is difficult to pronounce, it is thought that a natural
  **sound change (rendaku/nasalization)** occurred, shifting from "Nippon" to "Nihon."

Because of that,

• Traditional/slightly older sound → Nippon

• Modern/general sound → Nihon
  became the prevailing sense.

2. Discussions within the government from the Meiji era to the postwar period

Since the Meiji era, there have been many discussions in Japan about whether the reading should be unified.

However...

• Both have been used in administrative documents

• Both have continued to be widely used among the public

Therefore, they ultimately gave up on unification, and to this day, both are treated as correct.

3. Trends in usage by context

◆ Situations where "Nippon" is more commonly used

• Olympic cheering ("Ganbare! Nippon!")

• English lettering on coins and stamps (NIPPON)

• Situations where the airline Japan Airlines uses "Nippon"

• Company names and brand names (NIPPON...)

It is often chosen for images of strength, tradition, and dignity.

◆ Situations where "Nihon" is more commonly used

• Daily conversation

• General reading in news reports

• In school education, "Nihon" is also the standard

It is positioned as having a softer sound and being the natural, general everyday term.

4. Which is used more?

In modern times,
general conversation/media -> "Nihon" is dominant.
emphasis or patriotic expressions -> "Nippon" is adopted.

Depending on the survey, "Nihon" is sometimes cited as being used over 60% of the time.

5. Cultural and sensory differences (nuance)

• Nihon: softer, peaceful, everyday Japan

• Nippon: powerful, formal, Japan in contexts of tradition or representing the nation

These differences in nuance are often discussed.

Summary

ReadingNihonCorrect, soft, modern conversation, newsNipponCorrect, powerful, traditional sports cheering, coins, brand names

Both are official, and you may use them interchangeably depending on the context or nuance.

So both are official. Thanks to you, my question has been cleared up and I feel relieved.
Now I can get back to enjoying Korean dramas with full focus.

Thank you for humoring my simple questions again today.
See you later.
Annyeong (Goodbye).